// Numbas version: exam_results_page_options {"name": "Numbas v5.0", "metadata": {"description": "

A demo of the main new features in Numbas v5: explore mode, alternative answers and \"Choose from a menu\" question navigation.

", "licence": "Creative Commons Attribution 4.0 International"}, "duration": 0, "percentPass": "0", "showQuestionGroupNames": true, "shuffleQuestionGroups": false, "showstudentname": true, "question_groups": [{"name": "Explore mode", "pickingStrategy": "all-ordered", "pickQuestions": "1", "questionNames": ["", "", "", "", "", "", "", ""], "variable_overrides": [[], [], [], [], [], [], [], []], "questions": [{"name": "Decide if a coin is biased", "extensions": ["stats"], "custom_part_types": [{"source": {"pk": 1, "author": {"name": "Christian Lawson-Perfect", "pk": 7}, "edit_page": "/part_type/1/edit"}, "name": "Yes/no", "short_name": "yes-no", "description": "

The student is shown two radio choices: \"Yes\" and \"No\". One of them is correct.

", "help_url": "", "input_widget": "radios", "input_options": {"correctAnswer": "if(eval(settings[\"correct_answer_expr\"]), 0, 1)", "hint": {"static": true, "value": ""}, "choices": {"static": true, "value": ["Yes", "No"]}}, "can_be_gap": true, "can_be_step": true, "marking_script": "mark:\nif(studentanswer=correct_answer,\n correct(),\n incorrect()\n)\n\ninterpreted_answer:\nstudentAnswer=0\n\ncorrect_answer:\nif(eval(settings[\"correct_answer_expr\"]),0,1)", "marking_notes": [{"name": "mark", "description": "This is the main marking note. It should award credit and provide feedback based on the student's answer.", "definition": "if(studentanswer=correct_answer,\n correct(),\n incorrect()\n)"}, {"name": "interpreted_answer", "description": "A value representing the student's answer to this part.", "definition": "studentAnswer=0"}, {"name": "correct_answer", "description": "", "definition": "if(eval(settings[\"correct_answer_expr\"]),0,1)"}], "settings": [{"name": "correct_answer_expr", "label": "Is the answer \"Yes\"?", "help_url": "", "hint": "An expression which evaluates to true or false.", "input_type": "mathematical_expression", "default_value": "true", "subvars": false}], "public_availability": "always", "published": true, "extensions": []}], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Christian Lawson-Perfect", "profile_url": "http://localhost:8000/accounts/profile/1/"}, {"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}], "tags": [], "metadata": {"description": "An interactive experiment about probability: the student must first 'design' the experiment by deciding how many times they're going to flip a coin, and define what number of heads would make them believe the coin is biased. They must then enter the results of their coin flips, calculate the percentage of heads, and finally decide if the coin is biased, using the condition they specified in the design stage. There are optional hints at each stage.
", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "", "advice": "", "rulesets": {}, "variables": {"flips": {"name": "flips", "group": "Ungrouped variables", "definition": "parse_flips(flips_string)", "description": "", "templateType": "anything"}, "flips_string": {"name": "flips_string", "group": "Ungrouped variables", "definition": "join(repeat(random(\"h\",\"t\"),num_flips),\" \")", "description": "", "templateType": "anything"}, "num_flips": {"name": "num_flips", "group": "Ungrouped variables", "definition": "100", "description": "", "templateType": "anything"}, "num_heads": {"name": "num_heads", "group": "Ungrouped variables", "definition": "len(filter(x,x,flips))", "description": "", "templateType": "anything"}, "num_tails": {"name": "num_tails", "group": "Ungrouped variables", "definition": "len(flips)-num_heads", "description": "", "templateType": "anything"}, "percent_heads": {"name": "percent_heads", "group": "Ungrouped variables", "definition": "100*num_heads/len(flips)", "description": "", "templateType": "anything"}, "cleaned_flips_string": {"name": "cleaned_flips_string", "group": "Ungrouped variables", "definition": "join(map(if(x,\"H\",\"T\"),x,flips),\" \")", "description": "", "templateType": "anything"}, "critical_number": {"name": "critical_number", "group": "Ungrouped variables", "definition": "max(raw_critical_number, num_flips-raw_critical_number)", "description": "", "templateType": "anything"}, "is_biased": {"name": "is_biased", "group": "Ungrouped variables", "definition": "num_heads>=critical_number or num_tails>=critical_number", "description": "", "templateType": "anything"}, "raw_critical_number": {"name": "raw_critical_number", "group": "Ungrouped variables", "definition": "60", "description": "", "templateType": "anything"}, "critical_likelihood": {"name": "critical_likelihood", "group": "Ungrouped variables", "definition": "critical_number/num_flips", "description": "", "templateType": "anything"}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": ["num_flips", "raw_critical_number", "critical_number", "flips_string", "flips", "num_heads", "num_tails", "percent_heads", "cleaned_flips_string", "is_biased", "critical_likelihood"], "variable_groups": [], "functions": {"parse_flips": {"parameters": [["s", "string"]], "type": "list", "language": "javascript", "definition": "s = s.toLowerCase().replace(/[^ht]/g,'');\nreturn s.split('').map(function(c) { return new Numbas.jme.types.TBool(c=='h'); });"}}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "information", "useCustomName": true, "customName": "Introduction", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [{"label": "Decide number of flips", "rawLabel": "", "otherPart": 1, "variableReplacements": [], "availabilityCondition": "", "penalty": "", "penaltyAmount": 0, "lockAfterLeaving": false}], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "

In this exercise you will decide if a coin is biased by flipping it repeatedly and deciding if it lands heads more often than you'd expect.

"}, {"type": "numberentry", "useCustomName": true, "customName": "Decide number of flips", "marks": "1", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": false, "showFeedbackIcon": false, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [{"label": "Define 'biased'", "rawLabel": "", "otherPart": 2, "variableReplacements": [{"variable": "num_flips", "definition": "interpreted_answer"}], "availabilityCondition": "answered", "penalty": "", "penaltyAmount": 0, "lockAfterLeaving": false}], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": "Design the experiment", "prompt": "

How many times will you flip your coin?

", "minValue": "1", "maxValue": "infinity", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "Define 'biased'", "marks": 1, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": false, "showFeedbackIcon": false, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [{"label": "Enter data", "rawLabel": "", "otherPart": 4, "variableReplacements": [{"variable": "raw_critical_number", "definition": "interpreted_answer"}], "availabilityCondition": "answered and credit=1", "penalty": "", "penaltyAmount": 0, "lockAfterLeaving": false}, {"label": "What do you expect an unbiased coin do?", "rawLabel": "", "otherPart": 3, "variableReplacements": [], "availabilityCondition": "not (answered or credit=1)", "penalty": "", "penaltyAmount": 0, "lockAfterLeaving": false}], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": "Design the experiment", "prompt": "

How many heads would make you think the coin is biased?

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With an unbiased coin, how many flips would you expect to land heads up?

", "minValue": "num_flips/2-0.5", "maxValue": "num_flips/2+0.5", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "patternmatch", "useCustomName": true, "customName": "Enter data", "marks": "1", "scripts": {}, "customMarkingAlgorithm": "right_length:\n if(len(parse_flips(studentAnswer))=num_flips,\n correct(\"You have entered your data correctly.\"),\n incorrect(\"You have not entered the right number of flips.\")\n )\n\nmark:\n apply(right_length)\n", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": false, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [{"label": "Calculate proportion of heads", "rawLabel": "", "otherPart": 5, "variableReplacements": [{"variable": "flips_string", "definition": "interpreted_answer"}], "availabilityCondition": "answered", "penalty": "", "penaltyAmount": 0, "lockAfterLeaving": false}], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": "Enter data", "prompt": "

Flip the coin {num_flips} times. Each time it lands heads, write an H in the box below. Each time it lands tails, write a T.

", "answer": "[, hHtT]*", "displayAnswer": "", "matchMode": "regex"}, {"type": "numberentry", "useCustomName": true, "customName": "Calculate proportion of heads", "marks": "2", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [{"label": "Show frequencies of heads and tails", "rawLabel": "", "otherPart": 6, "variableReplacements": [], "availabilityCondition": "not (answered and credit=1)", "penalty": "Showed frequencies of heads and tails", "penaltyAmount": "1", "lockAfterLeaving": false}, {"label": "Is the coin biased?", "rawLabel": "", "otherPart": 7, "variableReplacements": [], "availabilityCondition": "answered", "penalty": "", "penaltyAmount": 0, "lockAfterLeaving": false}], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": "Calculate proportion of heads", "prompt": "

Your flips were:

\n

{cleaned_flips_string}

\n

What percentage of the flips landed heads?

", "minValue": "percent_heads", "maxValue": "percent_heads", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "precisionType": "dp", "precision": 0, "precisionPartialCredit": 0, "precisionMessage": "You have not given your answer to the correct precision.", "strictPrecision": false, "showPrecisionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "information", "useCustomName": true, "customName": "Show frequencies of heads and tails", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": true, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "\n\n\n\n\n\n\n\n\n\n\n\n\n
ResultHeadsTails
Frequency{num_heads}{num_tails}
"}, {"type": "yes-no", "useCustomName": true, "customName": "Is the coin biased?", "marks": "5", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [{"label": "Calculate the critical likelihood", "rawLabel": "", "otherPart": 8, "variableReplacements": [], "availabilityCondition": "not (answered and credit=1)", "penalty": "Hint about critical likelihood", "penaltyAmount": "1", "lockAfterLeaving": false}], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": "Decide if the coin is biased", "prompt": "

Do you think your coin is biased?

", "settings": {"correct_answer_expr": "is_biased"}}, {"type": "numberentry", "useCustomName": true, "customName": "Calculate the critical likelihood", "marks": 1, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": true, "adaptiveMarkingPenalty": 0, "exploreObjective": "Decide if the coin is biased", "prompt": "

You said that a coin is biased if it comes up heads at least {critical_number} times out of {num_flips}. What's that as a percentage?

", "minValue": "100*critical_likelihood", "maxValue": "100*critical_likelihood", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "precisionType": "dp", "precision": 0, "precisionPartialCredit": "100", "precisionMessage": "", "strictPrecision": false, "showPrecisionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}], "partsMode": "explore", "maxMarks": 0, "objectives": [{"name": "Calculate proportion of heads", "limit": "2", "mode": "sum"}, {"name": "Decide if the coin is biased", "limit": "5", "mode": "sum"}, {"name": "Design the experiment", "limit": "2", "mode": "sum"}, {"name": "Enter data", "limit": "1", "mode": "sum"}], "penalties": [{"name": "Showed frequencies of heads and tails", "limit": "1", "mode": "sum"}, {"name": "Hint about critical likelihood", "limit": "1", "mode": "sum"}], "objectiveVisibility": "always", "penaltyVisibility": "when-active"}, {"name": "Factorise a number", "extensions": ["stats"], "custom_part_types": [{"source": {"pk": 1, "author": {"name": "Christian Lawson-Perfect", "pk": 7}, "edit_page": "/part_type/1/edit"}, "name": "Yes/no", "short_name": "yes-no", "description": "

The student is shown two radio choices: \"Yes\" and \"No\". One of them is correct.

", "help_url": "", "input_widget": "radios", "input_options": {"correctAnswer": "if(eval(settings[\"correct_answer_expr\"]), 0, 1)", "hint": {"static": true, "value": ""}, "choices": {"static": true, "value": ["Yes", "No"]}}, "can_be_gap": true, "can_be_step": true, "marking_script": "mark:\nif(studentanswer=correct_answer,\n correct(),\n incorrect()\n)\n\ninterpreted_answer:\nstudentAnswer=0\n\ncorrect_answer:\nif(eval(settings[\"correct_answer_expr\"]),0,1)", "marking_notes": [{"name": "mark", "description": "This is the main marking note. It should award credit and provide feedback based on the student's answer.", "definition": "if(studentanswer=correct_answer,\n correct(),\n incorrect()\n)"}, {"name": "interpreted_answer", "description": "A value representing the student's answer to this part.", "definition": "studentAnswer=0"}, {"name": "correct_answer", "description": "", "definition": "if(eval(settings[\"correct_answer_expr\"]),0,1)"}], "settings": [{"name": "correct_answer_expr", "label": "Is the answer \"Yes\"?", "help_url": "", "hint": "An expression which evaluates to true or false.", "input_type": "mathematical_expression", "default_value": "true", "subvars": false}], "public_availability": "always", "published": true, "extensions": []}], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Christian Lawson-Perfect", "profile_url": "http://localhost:8000/accounts/profile/1/"}, {"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}], "tags": [], "metadata": {"description": "An example of an iterative procedure: the student must factorise a given number. At each step, they're asked if the number is factorised. If not, they must give a prime factor. If it is fully factorised, they can then work out the number of factors of the number.
", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "", "advice": "

This is advice.

", "rulesets": {}, "variables": {"n": {"name": "n", "group": "Ungrouped variables", "definition": "prod(actual_factors)", "description": "

The number to factorise.

", "templateType": "anything"}, "factors": {"name": "factors", "group": "Ungrouped variables", "definition": "[]", "description": "

The prime factors entered by the student.

", "templateType": "anything"}, "fully_factorised": {"name": "fully_factorised", "group": "Ungrouped variables", "definition": "all(map(mod(current_n,k)<>0,k,2..floor(sqrt(current_n))))", "description": "

Is the number fully factorised? True if no integer between 2 and $\\sqrt{\\texttt{current_n}}$ divides current_n, so it's prime.

", "templateType": "anything"}, "current_n": {"name": "current_n", "group": "Ungrouped variables", "definition": "n/prod(factors)", "description": "

The part of $n$ still left to factorise.

", "templateType": "anything"}, "weighted_primes": {"name": "weighted_primes", "group": "Ungrouped variables", "definition": "[2,2,2,2,3,3,3,5,5,7,11]", "description": "

A list of prime numbers, weighted so smaller primes are picked more often

", "templateType": "anything"}, "num_factors": {"name": "num_factors", "group": "Ungrouped variables", "definition": "prod(map(len(filter(x=k,x,actual_factors))+1,k,set(actual_factors)))", "description": "

The number of factors of $n$.

", "templateType": "anything"}, "actual_factors": {"name": "actual_factors", "group": "Ungrouped variables", "definition": "repeat(random(weighted_primes),3)", "description": "

Pick three (not necessarily unique) prime factors for $n$.

", "templateType": "anything"}, "factorisation_latex": {"name": "factorisation_latex", "group": "Ungrouped variables", "definition": "latex(current_n+if(len(factors),' \\\\times '+join(factors,' \\\\times '),''))", "description": "

LaTeX expression showing the current statre of the factorisation.

", "templateType": "anything"}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": ["weighted_primes", "actual_factors", "n", "factors", "fully_factorised", "current_n", "num_factors", "factorisation_latex"], "variable_groups": [], "functions": {"isprime": {"parameters": [["n", "number"]], "type": "boolean", "language": "jme", "definition": "n>=2 and isint(n) and all(map(mod(n,k)>0,k,2..floor(sqrt(n))))"}}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "yes-no", "useCustomName": true, "customName": "Is it factorised?", "marks": "0", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [{"label": "Write a factor", "rawLabel": "", "otherPart": 1, "variableReplacements": [], "availabilityCondition": "not interpreted_answer", "penalty": "", "penaltyAmount": 0, "lockAfterLeaving": false}, {"label": "How many factors?", "rawLabel": "", "otherPart": 2, "variableReplacements": [], "availabilityCondition": "interpreted_answer", "penalty": "", "penaltyAmount": 0, "lockAfterLeaving": false}], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "

Is $\\var{n} = \\var{factorisation_latex}$ fully factorised?

", "settings": {"correct_answer_expr": "fully_factorised"}}, {"type": "numberentry", "useCustomName": true, "customName": "Write a factor", "marks": "1", "scripts": {}, "customMarkingAlgorithm": "is_factor:\n if(mod(current_n,studentNumber)=0,\n if(isprime(studentNumber),\n correct()\n ,\n set_credit(0.5,\"Your answer is a factor of {current_n} but is not prime.\")\n )\n ,\n incorrect(\"Your answer is not a factor of {current_n}\")\n )\n \n\nmark (Mark the student's answer):\n apply(validNumber);\n apply(is_factor)", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [{"label": "Is it factorised?", "rawLabel": "", "otherPart": 0, "variableReplacements": [{"variable": "factors", "definition": "factors+[interpreted_answer]"}], "availabilityCondition": "answered and credit=1", "penalty": "", "penaltyAmount": 0, "lockAfterLeaving": false}], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": "Identify the factors of $\\var{n}$", "prompt": "

Write a prime factor of $\\var{current_n}$.

", "minValue": "1", "maxValue": "1", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "How many factors?", "marks": "2", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": "Calculate how many factors", "prompt": "

How many factors does $\\var{n} = \\var{factorisation_latex}$ have?

", "minValue": "num_factors", "maxValue": "num_factors", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}], "partsMode": "explore", "maxMarks": "4", "objectives": [{"name": "Identify the factors of $\\var{n}$", "limit": "3", "mode": "sum"}, {"name": "Calculate how many factors", "limit": "2", "mode": "sum"}], "penalties": [], "objectiveVisibility": "always", "penaltyVisibility": "always"}, {"name": "Find Dracula", "extensions": ["stats"], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Christian Lawson-Perfect", "profile_url": "http://localhost:8000/accounts/profile/1/"}, {"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}], "tags": [], "metadata": {"description": "This question demonstrates how to use explore mode to simulate a game, where each choice made by the student changes the state of the game.
", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "

You're trying to find Dracula. You've reached the grand gallery of Castle Dracula, and you know that the Count is hiding in one of the rooms. But which?

\n

All the rooms are on one side of the gallery. They each have internal doors between them, that only Dracula can use. Each time you look in a room that Dracula isn't in, he moves from the room he's in to an adjacent one.

\n

Can you find Dracula?

", "advice": "", "rulesets": {}, "variables": {"cells": {"name": "cells", "group": "Ungrouped variables", "definition": "repeat(true,n)", "description": "

For each room, whether Dracula can be in that room.

", "templateType": "anything"}, "n": {"name": "n", "group": "Ungrouped variables", "definition": "4", "description": "

The number of rooms

", "templateType": "anything"}, "cells_after_pick": {"name": "cells_after_pick", "group": "Ungrouped variables", "definition": "map(\n let(ncells,map(if(k=j,false,cells[k]),k,0..n-1),\n map(if(k>0,ncells[k-1],false) or if(kFor each room, the value of cells after looking in that room.

", "templateType": "anything"}, "room_names": {"name": "room_names", "group": "Ungrouped variables", "definition": "map(\"Room \"+j,j,1..n)", "description": "

The names of the rooms, for display.

", "templateType": "anything"}, "dracula": {"name": "dracula", "group": "Ungrouped variables", "definition": "random(0..n-1)", "description": "

The room Dracula is in.

", "templateType": "anything"}, "dracula_choices": {"name": "dracula_choices", "group": "Ungrouped variables", "definition": "switch(\n dracula=0,[1],\n dracula=n-1,[n-2],\n [dracula-1,dracula+1]\n)", "description": "

The rooms Dracula can move to.

", "templateType": "anything"}, "chosen_room": {"name": "chosen_room", "group": "Ungrouped variables", "definition": "0", "description": "

The last room that was looked in.

", "templateType": "anything"}, "look_marking": {"name": "look_marking", "group": "Ungrouped variables", "definition": "map(award(1,j=dracula),j,0..n-1)", "description": "

Award 1 mark for looking in the room containing Dracula.

", "templateType": "anything"}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": ["n", "dracula", "cells", "cells_after_pick", "room_names", "dracula_choices", "chosen_room", "look_marking"], "variable_groups": [], "functions": {}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "numberentry", "useCustomName": true, "customName": "How many rooms does Castle Dracula have?", "marks": 1, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": false, "showFeedbackIcon": false, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [{"label": "Look in a room", "rawLabel": "", "otherPart": 1, "variableReplacements": [{"variable": "n", "definition": "interpreted_answer"}], "availabilityCondition": "answered", "penalty": "", "penaltyAmount": 0, "lockAfterLeaving": false}], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "

How many rooms does Castle Dracula have?

\n

(You can pick - a smaller number is easier, while a larger number will mean it takes longer to find Dracula)

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Which room would you like to look in now?

", "minMarks": 0, "maxMarks": 0, "shuffleChoices": false, "displayType": "radiogroup", "displayColumns": 0, "showCellAnswerState": true, "choices": "map(\"Room \"+j,j,1..n)", "matrix": "repeat(0,n)"}, {"type": "information", "useCustomName": true, "customName": "Dracula wasn't in the room", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [{"label": "Where could Dracula be?", "rawLabel": "", "otherPart": 3, "variableReplacements": [], "availabilityCondition": "", "penalty": "", "penaltyAmount": 0, "lockAfterLeaving": false}, {"label": "Look in another room", "rawLabel": "Look in another room", "otherPart": 1, "variableReplacements": [], "availabilityCondition": "", "penalty": "", "penaltyAmount": 0, "lockAfterLeaving": false}], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "

Dracula wasn't in room {chosen_room+1}. Drat!

\n

You go back to the hall, and close the door. Dracula leaves the room he is in and moves to an adjacent room.

"}, {"type": "m_n_2", "useCustomName": true, "customName": "Where could Dracula be?", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": false, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": true, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "

Which rooms could Dracula be in right now?

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You open the door and find the dread Count himself!

\n

What do you do?

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", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "", "advice": "", "rulesets": {}, "variables": {"a": {"name": "a", "group": "Ungrouped variables", "definition": "random(1 .. 9#1)", "description": "", "templateType": "randrange"}, "b": {"name": "b", "group": "Ungrouped variables", "definition": "random(2 .. 5#1)", "description": "", "templateType": "randrange"}, "c": {"name": "c", "group": "Ungrouped variables", "definition": "random(2 .. 5#1)", "description": "", "templateType": "randrange"}, "d": {"name": "d", "group": "Ungrouped variables", "definition": "random(-5..5 except 0)", "description": "", "templateType": "anything"}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": ["a", "b", "c", "d"], "variable_groups": [], "functions": {}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "numberentry", "useCustomName": true, "customName": "Evaluate an expression", "marks": 1, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [{"label": "Get a hint", "rawLabel": "Get a hint", "otherPart": 1, "variableReplacements": [], "availabilityCondition": "interpreted_answer=(a+b)*c+d", "penalty": "Hint", "penaltyAmount": "0.5", "lockAfterLeaving": false}], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": "Evaluate an expression", "prompt": "

What is $\\simplify[]{ {a} + {b}*{c} + {d} }$?

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Did you evaluate the expression from left to right, without accounting for the order of operations?

\n

Perform multiplication first: $\\simplify[]{ {a} + {b}*{c} + {d} } = \\simplify[]{ {a} + {b*c} + {d} }$

"}], "partsMode": "explore", "maxMarks": 0, "objectives": [{"name": "Evaluate an expression", "limit": 1, "mode": "sum"}], "penalties": [{"name": "Hint", "limit": "0.5", "mode": "sum"}], "objectiveVisibility": "always", "penaltyVisibility": "always"}, {"name": "Lock a part after leaving it", "extensions": ["stats"], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Christian Lawson-Perfect", "profile_url": "http://localhost:8000/accounts/profile/1/"}, {"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}], "tags": [], "metadata": {"description": "This question demonstrates how to lock a part in explore mode after moving to the next part, to prevent the student changing their answer and invalidating the rest of the question.
", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "", "advice": "", "rulesets": {}, "variables": {"x": {"name": "x", "group": "Ungrouped variables", "definition": "1", "description": "", "templateType": "anything"}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": ["x"], "variable_groups": [], "functions": {}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "numberentry", "useCustomName": true, "customName": "Enter a number", "marks": "0", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [{"label": "Double the number", "rawLabel": "", "otherPart": 1, "variableReplacements": [{"variable": "x", "definition": "interpreted_answer"}], "availabilityCondition": "answered", "penalty": "", "penaltyAmount": 0, "lockAfterLeaving": true}, {"label": "Get some inspiration", "rawLabel": "", "otherPart": 2, "variableReplacements": [], "availabilityCondition": "not (answered and credit=1)", "penalty": "", "penaltyAmount": 0, "lockAfterLeaving": false}], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "

Write a number.

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$x = \\var{x}$.

\n

What is $2x$?

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Maybe you'd like to write the number {random(100..200)}?

"}], "partsMode": "explore", "maxMarks": 0, "objectives": [{"name": "Double the number", "limit": 1, "mode": "sum"}], "penalties": [], "objectiveVisibility": "always", "penaltyVisibility": "always"}, {"name": "Posting a parcel", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false}, "contributors": [{"name": "Christian Lawson-Perfect", "profile_url": "http://localhost:8000/accounts/profile/1/"}, {"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}], "tags": [], "metadata": {"description": "An interactive activity: the student enters the dimensions of a parcel, then has to calculate its volume, and classify its size by comparing against a table of maximum dimensions.
", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "", "advice": "", "rulesets": {}, "variables": {"width": {"name": "width", "group": "Ungrouped variables", "definition": "10", "description": "", "templateType": "anything"}, "length": {"name": "length", "group": "Ungrouped variables", "definition": "10", "description": "", "templateType": "anything"}, "height": {"name": "height", "group": "Ungrouped variables", "definition": "3", "description": "", "templateType": "anything"}, "volume": {"name": "volume", "group": "Ungrouped variables", "definition": "width*length*height", "description": "", "templateType": "anything"}, "sizes": {"name": "sizes", "group": "Ungrouped variables", "definition": "[\n [name: \"Small\", width: 20, length: 20, height: 5, volume: 300],\n [name: \"Medium\", width: 40, length: 40, height: 30, volume: 6000],\n [name: \"Large\", width: 60, length: 60, height: 60, volume: 27000],\n [name: \"Too large\", width: infinity, length: infinity, height: infinity, volume: infinity]\n]", "description": "", "templateType": "anything"}, "valid_sizes": {"name": "valid_sizes", "group": "Ungrouped variables", "definition": "map(\n let(\n sdims,sort([size[\"width\"],size[\"height\"],size[\"length\"]])+[size[\"volume\"]],\n all(map(x<=y,[x,y],zip(dimensions,sdims)))\n )\n ,\n size,\n sizes\n)", "description": "", "templateType": "anything"}, "dimensions": {"name": "dimensions", "group": "Ungrouped variables", "definition": "sort([width,length,height])+[volume]", "description": "", "templateType": "anything"}, "best_size": {"name": "best_size", "group": "Ungrouped variables", "definition": "filter(valid_sizes[j],j,0..len(sizes)-1)[0]", "description": "", "templateType": "anything"}, "size_table": {"name": "size_table", "group": "Ungrouped variables", "definition": "table(\n map(\n [size[\"name\"],size[\"width\"],size[\"length\"],size[\"height\"], separateThousands(size[\"volume\"],\",\")],\n size,\n sizes[0..len(sizes)-1]\n ),\n [\"Size\", \"Max. width (cm)\", \"Max. length (cm)\", \"Max. height (cm)\", \"Max. volume (cm\u00b3)\"]\n)", "description": "", "templateType": "anything"}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": ["width", "length", "height", "volume", "dimensions", "sizes", "valid_sizes", "best_size", "size_table"], "variable_groups": [], "functions": {}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "information", "useCustomName": true, "customName": "Introduction", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [{"label": "Enter the parcel's measurements", "rawLabel": "", "otherPart": 1, "variableReplacements": [], "availabilityCondition": "", "penalty": "", "penaltyAmount": 0, "lockAfterLeaving": false}], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "

You would like to post a parcel. The cost of postage depends on the size of your parcel.

"}, {"type": "gapfill", "useCustomName": true, "customName": "Enter the parcel's measurements", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [{"label": "Calculate volume", "rawLabel": "", "otherPart": 2, "variableReplacements": [{"variable": "width", "definition": "interpreted_answer[0]"}, {"variable": "height", "definition": "interpreted_answer[1]"}, {"variable": "length", "definition": "interpreted_answer[2]"}], "availabilityCondition": "answered", "penalty": "", "penaltyAmount": 0, "lockAfterLeaving": false}], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "

Enter the dimensions of your parcel, in centimetres.

\n

Width: [[0]]

\n

Length: [[1]]

\n

Height: [[2]]

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Your parcel measures $\\var{width} \\times \\var{length} \\times \\var{height}$cm.

\n

What is the volume of your parcel, in cubic centimetres?

", "minValue": "volume", "maxValue": "volume", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "1_n_2", "useCustomName": true, "customName": "Pick the appropriate size", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": "Pick the size of the parcel", "prompt": "

The post company categorises parcels according to the following table:

\n

{size_table}

\n

What size is your parcel?

", "minMarks": 0, "maxMarks": 0, "shuffleChoices": false, "displayType": "radiogroup", "displayColumns": 0, "showCellAnswerState": true, "choices": "map(size[\"name\"],size,sizes)", "matrix": "map(award(1,x=best_size), x, 0..len(sizes)-1)"}], "partsMode": "explore", "maxMarks": 0, "objectives": [{"name": "Calculate the parcel's volume", "limit": "1", "mode": "sum"}, {"name": "Pick the size of the parcel", "limit": "1", "mode": "sum"}], "penalties": [], "objectiveVisibility": "always", "penaltyVisibility": "always"}, {"name": "Offer hints at different levels of detail", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false}, "contributors": [{"name": "Christian Lawson-Perfect", "profile_url": "http://localhost:8000/accounts/profile/1/"}, {"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}], "tags": [], "metadata": {"description": "This question demonstrates how you can offer a selection of hints, with each giving a different level of detail and applying a different penalty.
", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "", "advice": "", "rulesets": {}, "variables": {}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": [], "variable_groups": [], "functions": {}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "numberentry", "useCustomName": true, "customName": "Write a number", "marks": "10", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [{"label": "Vague hint", "rawLabel": "", "otherPart": 1, "variableReplacements": [], "availabilityCondition": "", "penalty": "Hints revealed", "penaltyAmount": "1", "lockAfterLeaving": false}, {"label": "More specific hint", "rawLabel": "", "otherPart": 2, "variableReplacements": [], "availabilityCondition": "", "penalty": "Hints revealed", "penaltyAmount": "2", "lockAfterLeaving": false}, {"label": "Guided steps", "rawLabel": "", "otherPart": 3, "variableReplacements": [], "availabilityCondition": "", "penalty": "Hints revealed", "penaltyAmount": "3", "lockAfterLeaving": false}], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": "Write the number 3435", "prompt": "

In this question, you need to write the number 3435.

\n

If you need help, ask for a hint.

", "minValue": "3435", "maxValue": "3435", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "information", "useCustomName": true, "customName": "Vague hint", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": true, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "

The thing you need to write is an integer.

"}, {"type": "information", "useCustomName": true, "customName": "More specific hint", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": true, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "

Use the digit keys on your keyboard to write the number.

"}, {"type": "gapfill", "useCustomName": true, "customName": "Guided steps", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": true, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "

Try writing the digits one at a time.

\n

Write 3: [[0]]

\n

Write 4: [[1]]

\n

Write 3 again: [[2]]

\n

Write 5: [[3]]

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$f(x) = \\simplify{{c1}x^2 + {c2}x + {c3}}$

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50% chance of being the same as root1

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How many distinct solutions does $f(x)=0$ have?

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Write the two roots, $x_1$ and $x_2$, of the equation $f(x)=0$, such that $x_1 \\lt x_2$:

\n

$x_1 = $ [[0]]

\n

$x_2 = $ [[1]]

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What is the discriminant of $f(x)$?

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For a quadratic equation in the form $ax^2 + bx + c$, the discriminant $D$ is

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\\[ D = b^2-4ac \\]

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The number of distinct roots of the equation depends on the value of the discriminant:

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The student must calculate the number of digits a given decimal number would have when written in a different base. Alternative answers catch some common mal-rules and give appropriate feedback.

Based on table 2 from \"diagnosing student errors in e-assessment questions\" by Philip Walker, D. Rhys Gwynllyw and Karen L. Henderson.

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How many digits does $\\var{n}_{10}$ have in base $\\var{b}$?

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You converted $\\var{n}$ to base $b$. You were asked to give the number of digits in this representation.

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You have multiplied $\\var{n}$ and $\\var{b}$ together. You were asked to calculate how many digits the base-$\\var{b}$ representation of $\\var{n}$ has.

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Did you calculate $\\simplify{floor(log({n},{b}))}$?

\n

Consider the following example:

\n

$\\simplify{floor(log(13,10))} = 1$, but $13$ has two digits.

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Did you calculate $\\simplify{floor(log({n},{b}))}-1$?

\n

Consider the following example:

\n

$\\simplify{floor(log(13,10))}-1 = 0$, but $13$ has two digits.

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Did you calculate $\\simplify{ceil(log({n},{b}))}+1$? You might have made an off-by-one error.

\n

Consider the following example:

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$\\simplify{ceil(log(13,10))}+1 = 3$, but $13$ has two digits.

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Write a number whose square is $\\var{n^2}$.

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Write $\\frac{3}{5}$ to two decimal places.

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You've written the right number, but you haven't included a trailing zero.

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While $0.6$ and represent the same number as $0.60$, they do not convey the same amount of precision. You must include zeros at the end of the number to make up the required number of decimal places.

"}], "partsMode": "explore", "maxMarks": 0, "objectives": [{"name": "Write to 2 decimal places", "limit": "1", "mode": "sum"}], "penalties": [], "objectiveVisibility": "always", "penaltyVisibility": "always"}, {"name": "Alternative answers: expanding range of accepted answers", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false}, "contributors": [{"name": "Christian Lawson-Perfect", "profile_url": "http://localhost:8000/accounts/profile/1/"}, {"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}], "tags": [], "metadata": {"description": "The student is asked to add two four-digit numbers. Alternative answers are set up with progressively expanding ranges of accepted values, so the student gets more marks for getting closer to the true answer.
", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "", "advice": "", "rulesets": {}, "variables": {"a": {"name": "a", "group": "Ungrouped variables", "definition": "random(1001 .. 8888#1)", "description": "", "templateType": "randrange"}, "b": {"name": "b", "group": "Ungrouped variables", "definition": "random(1001..9999-a)", "description": "", "templateType": "anything"}, "total": {"name": "total", "group": "Ungrouped variables", "definition": "a+b", "description": "", "templateType": "anything"}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": ["a", "b", "total"], "variable_groups": [], "functions": {}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "numberentry", "useCustomName": true, "customName": "Add two numbers", "marks": "5", "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "

Calculate $\\var{a} + \\var{b}$.

\n

(Try getting the answer slightly wrong: you're awarded more marks the closer you get to the correct answer.)

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You're within 10 of the correct answer.

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You're within 100 of the correct answer.

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You're within 1000 of the correct answer.

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Numbas v5 introduces the \"explore mode\" for questions, alternative answers for individual parts, and the \"Choose from a menu\" navigation mode for exams.

\n

The questions below demonstrate the new features in v5. Try them out!

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The student is shown two radio choices: \"Yes\" and \"No\". One of them is correct.

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