// Numbas version: exam_results_page_options {"name": "Maria's copy of Probability independent", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"functions": {}, "name": "Maria's copy of Probability independent", "metadata": {"description": "

rebelmaths

", "licence": "Creative Commons Attribution 4.0 International"}, "extensions": [], "ungrouped_variables": ["y", "thing", "x", "a1d", "a2", "a3", "a4", "a1", "a2d", "a3d", "a4d"], "tags": ["rebelmaths"], "parts": [{"precisionPartialCredit": 0, "variableReplacementStrategy": "originalfirst", "scripts": {}, "minValue": "{x}*{y}", "maxValue": "{x}*{y}", "precisionMessage": "You have not given your answer to the correct precision.", "showCorrectAnswer": true, "marks": "2", "variableReplacements": [], "correctAnswerFraction": false, "prompt": "

What is the probabilty that both of these events occur?

", "strictPrecision": false, "type": "numberentry", "showPrecisionHint": false, "allowFractions": false, "precisionType": "dp", "precision": "2"}, {"precisionPartialCredit": 0, "variableReplacementStrategy": "originalfirst", "scripts": {}, "minValue": "(1-{x})*(1-{y})", "maxValue": "(1-{x})*(1-{y})", "precisionMessage": "You have not given your answer to the correct precision.", "showCorrectAnswer": true, "marks": "2", "variableReplacements": [], "correctAnswerFraction": false, "prompt": "

What is the probabilty that neither of these events occur?

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What is the probabilty that at least one of these two events will occur?

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What is the probabilty that only one of the two events occur?

", "strictPrecision": false, "type": "numberentry", "showPrecisionHint": false, "allowFractions": false, "precisionType": "dp", "precision": "2"}], "rulesets": {}, "variables": {"a4d": {"description": "", "name": "a4d", "templateType": "anything", "group": "Ungrouped variables", "definition": "precround((1-x)*y+(1-y)*x,2)"}, "a4": {"description": "", "name": "a4", "templateType": "anything", "group": "Ungrouped variables", "definition": "(1-x)*y+(1-y)*x"}, "a1": {"description": "", "name": "a1", "templateType": "anything", "group": "Ungrouped variables", "definition": "x*y"}, "a3": {"description": "", "name": "a3", "templateType": "anything", "group": "Ungrouped variables", "definition": "1-a2"}, "thing": {"description": "", "name": "thing", "templateType": "anything", "group": "Ungrouped variables", "definition": "random(['there will be a change in government in Ireland next year ', 'Ireland will win the rugby world cup next year'],['it will rain in Qumar on any given day','it will rain in Timbucktoo on any given day'],['shares in the Bank of Lapland will rise on any given day','shares in the Bank of Never Never Land will rise on any given day'])"}, "x": {"description": "", "name": "x", "templateType": "randrange", "group": "Ungrouped variables", "definition": "random(0.01..0.9#0.01)"}, "a3d": {"description": "", "name": "a3d", "templateType": "anything", "group": "Ungrouped variables", "definition": "precround(1-a2,2)"}, "a2": {"description": "", "name": "a2", "templateType": "anything", "group": "Ungrouped variables", "definition": "(1-x)*(1-y)"}, "a1d": {"description": "", "name": "a1d", "templateType": "anything", "group": "Ungrouped variables", "definition": "precround(x*y,2)"}, "a2d": {"description": "", "name": "a2d", "templateType": "anything", "group": "Ungrouped variables", "definition": "precround((1-x)*(1-y),2)"}, "y": {"description": "", "name": "y", "templateType": "randrange", "group": "Ungrouped variables", "definition": "random(0.01..0.99#0.01)"}}, "preamble": {"css": "", "js": ""}, "question_groups": [{"pickQuestions": 0, "name": "", "pickingStrategy": "all-ordered", "questions": []}], "variable_groups": [], "variablesTest": {"condition": "", "maxRuns": 100}, "statement": "

The probability that {thing[0]} is {x}, while the probability that {thing[1]} is {y}. Assume that these two events are independent. Give all answers correct to two decimal places.

", "type": "question", "advice": "

(a) P({thing[0]})xP({thing[1]})={x}x{y}={a1}

\n

Next round to 2 decimal places to get {a1d}

\n

(b) P(not - {thing[0]})xP(not - {thing[1]})$=(1-\\var{x})\\times (1-\\var{y})=\\var{a2}$

\n

Next round to 2 decimal places to get {a2d}

\n

(c) 1- (answer to part (b))=1-{a2d}={a3d}

\n

(d) ( (1-{x})x {y})+( (1-{y})x {x})={a4}

\n

Next round to 2 decimal places to get {a4d}

\n

", "showQuestionGroupNames": false, "contributors": [{"name": "Julie Crowley", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/113/"}, {"name": "Maria Aneiros", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/3388/"}]}]}], "contributors": [{"name": "Julie Crowley", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/113/"}, {"name": "Maria Aneiros", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/3388/"}]}