// Numbas version: exam_results_page_options {"name": "L1 - Matrix multiplication (selfstudy)", "extensions": ["stats"], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"functions": {}, "rulesets": {"std": ["all", "!collectNumbers", "fractionNumbers", "!noLeadingMinus"]}, "metadata": {"licence": "Creative Commons Attribution 4.0 International", "description": "

Exercises in multiplying matrices. 

"}, "variablesTest": {"condition": "", "maxRuns": 100}, "name": "L1 - Matrix multiplication (selfstudy)", "ungrouped_variables": ["ba21", "a21", "a22", "a23", "b23", "b22", "b21", "ba22", "w3", "w2", "w1", "ba11", "a11", "p1", "q1", "q3", "q2", "ab23", "ab22", "ab21", "s3", "s2", "s1", "a12", "s7", "s6", "s5", "s4", "b12", "b13", "b11", "c13", "c12", "c11", "a33", "a32", "a31", "ba32", "ba33", "a13", "ba31", "s10", "s9", "b32", "b31", "v1", "v2", "v3", "mae", "mad", "mag", "mah", "ba12", "ba13", "b33", "p2", "p3", "ba23", "ab11", "s8", "ab31", "ab32", "ab33", "ab12", "m", "mac", "n", "q", "p", "s", "r", "u", "w", "v", "y", "x", "z", "ab13"], "extensions": ["stats"], "variable_groups": [], "advice": "", "variables": {"mah": {"group": "Ungrouped variables", "name": "mah", "templateType": "anything", "description": "", "definition": "matrix(repeat(repeat(random(-2..9),x),y))"}, "ab31": {"group": "Ungrouped variables", "name": "ab31", "templateType": "anything", "description": "", "definition": "a31*b11+a32*b21+a33*b31"}, "w3": {"group": "Ungrouped variables", "name": "w3", "templateType": "anything", "description": "", "definition": "random(-4..4)"}, "b33": {"group": "Ungrouped variables", "name": "b33", "templateType": "anything", "description": "", "definition": "random(-2..2)"}, "ba33": {"group": "Ungrouped variables", "name": "ba33", "templateType": "anything", "description": "", "definition": "b31*a13+b32*a23+b33*a33"}, "b31": {"group": "Ungrouped variables", "name": "b31", "templateType": "anything", "description": "", "definition": "random(1..3)"}, "q": {"group": "Ungrouped variables", "name": "q", "templateType": "anything", "description": "", "definition": "m+random(0,z)"}, "ab11": {"group": "Ungrouped variables", "name": "ab11", "templateType": "anything", "description": "", "definition": "a11*b11+a12*b21+a13*b31"}, "s7": {"group": "Ungrouped variables", "name": "s7", "templateType": "anything", "description": "", "definition": "if(u=y,0.5,-0.5)"}, "ab21": {"group": "Ungrouped variables", "name": "ab21", "templateType": "anything", "description": "", "definition": "a21*b11+a22*b21+a23*b31"}, "mac": {"group": "Ungrouped variables", "name": "mac", "templateType": "anything", "description": "", "definition": "matrix(repeat(repeat(random(-2..9),n),m))"}, "s3": {"group": "Ungrouped variables", "name": "s3", "templateType": "anything", "description": "", "definition": "if(s=5,0.5,-0.5)"}, "b32": {"group": "Ungrouped variables", "name": "b32", "templateType": "anything", "description": "", "definition": "random(-3..3)"}, "r": {"group": "Ungrouped variables", "name": "r", "templateType": "anything", "description": "", "definition": "random(1..3)"}, "v3": {"group": "Ungrouped variables", "name": "v3", "templateType": "anything", "description": "", "definition": "random(-5..5)"}, "u": {"group": "Ungrouped variables", "name": "u", "templateType": "anything", "description": "", "definition": "random(3..4)"}, "c11": {"group": "Ungrouped variables", "name": "c11", "templateType": "anything", "description": "", "definition": "random(-2..2)"}, "b23": {"group": "Ungrouped variables", "name": "b23", "templateType": "anything", "description": "", "definition": "random(1,2)"}, "a32": {"group": "Ungrouped variables", "name": "a32", "templateType": "anything", "description": "", "definition": "random(-4..4)"}, "v1": {"group": "Ungrouped variables", "name": "v1", "templateType": "anything", "description": "", "definition": "random(-3..3)"}, "b21": {"group": "Ungrouped variables", "name": "b21", "templateType": "anything", "description": "", "definition": "random(0..2)"}, "ba22": {"group": "Ungrouped variables", "name": "ba22", "templateType": "anything", "description": "", "definition": "b21*a12+b22*a22+b23*a32"}, "ab33": {"group": "Ungrouped variables", "name": "ab33", "templateType": "anything", "description": "", "definition": "a31*b13+a32*b23+a33*b33"}, "mag": {"group": "Ungrouped variables", "name": "mag", "templateType": "anything", "description": "", "definition": "matrix(repeat(repeat(random(-2..9),u),w))"}, "a12": {"group": "Ungrouped variables", "name": "a12", "templateType": "anything", "description": "", "definition": "random(-1,1,2)"}, "s2": {"group": "Ungrouped variables", "name": "s2", "templateType": "anything", "description": "", "definition": "if(q=m,0.5,-0.5)"}, "ab13": {"group": "Ungrouped variables", "name": "ab13", "templateType": "anything", "description": "", "definition": "a11*b13+a12*b23+a13*b33"}, "b13": {"group": "Ungrouped variables", "name": "b13", "templateType": "anything", "description": "", "definition": "random(-2..2)"}, "m": {"group": "Ungrouped variables", "name": "m", "templateType": "anything", "description": "", "definition": "random(3..4)"}, "w": {"group": "Ungrouped variables", "name": "w", "templateType": "anything", "description": "", "definition": "random(3..5)"}, "q1": {"group": "Ungrouped variables", "name": "q1", "templateType": "anything", "description": "", "definition": "b11*w1+b12*w2+b13*w3"}, "ba12": {"group": "Ungrouped variables", "name": "ba12", "templateType": "anything", "description": "", "definition": "b11*a12+b12*a22+b13*a32"}, "s8": {"group": "Ungrouped variables", "name": "s8", "templateType": "anything", "description": "", "definition": "if(x=r,0.5,-0.5)"}, "mad": {"group": "Ungrouped variables", "name": "mad", "templateType": "anything", "description": "", "definition": "matrix(repeat(repeat(random(-2..9),q),p))"}, "s4": {"group": "Ungrouped variables", "name": "s4", "templateType": "anything", "description": "", "definition": "if(r=2,0.5,-0.5)"}, "z": {"group": "Ungrouped variables", "name": "z", "templateType": "anything", "description": "", "definition": "random(-2,-1,1,2)"}, "ba23": {"group": "Ungrouped variables", "name": "ba23", "templateType": "anything", "description": "", "definition": "b21*a13+b22*a23+b23*a33"}, "s10": {"group": "Ungrouped variables", "name": "s10", "templateType": "anything", "description": "", "definition": "if(u=3,0.5,-0.5)"}, "w1": {"group": "Ungrouped variables", "name": "w1", "templateType": "anything", "description": "", "definition": "random(4..6)"}, "c13": {"group": "Ungrouped variables", "name": "c13", "templateType": "anything", "description": "", "definition": "random(1..2)"}, "ba11": {"group": "Ungrouped variables", "name": "ba11", "templateType": "anything", "description": "", "definition": "b11*a11+b12*a21+b13*a31"}, "s5": {"group": "Ungrouped variables", "name": "s5", "templateType": "anything", "description": "", "definition": "if(m=3,0.5,-0.5)"}, "y": {"group": "Ungrouped variables", "name": "y", "templateType": "anything", "description": "", "definition": "u+random(0,z)"}, "ba31": {"group": "Ungrouped variables", "name": "ba31", "templateType": "anything", "description": "", "definition": "b31*a11+b32*a21+b33*a31"}, "s1": {"group": "Ungrouped variables", "name": "s1", "templateType": "anything", "description": "", "definition": "if(n=p,0.5,-0.5)"}, "ab22": {"group": "Ungrouped variables", "name": "ab22", "templateType": "anything", "description": "", "definition": "a21*b12+a22*b22+a23*b32"}, "a22": {"group": "Ungrouped variables", "name": "a22", "templateType": "anything", "description": "", "definition": "random(-4,-3,-2,-1,1,2,3,5)"}, "a21": {"group": "Ungrouped variables", "name": "a21", "templateType": "anything", "description": "", "definition": "random(-1,0,1)"}, "p3": {"group": "Ungrouped variables", "name": "p3", "templateType": "anything", "description": "", "definition": "a31*v1+a32*v2+a33*v3"}, "ba32": {"group": "Ungrouped variables", "name": "ba32", "templateType": "anything", "description": "", "definition": "b31*a12+b32*a22+b33*a32"}, "ba21": {"group": "Ungrouped variables", "name": "ba21", "templateType": "anything", "description": "", "definition": "b21*a11+b22*a21+b23*a31"}, "q3": {"group": "Ungrouped variables", "name": "q3", "templateType": "anything", "description": "", "definition": "b31*w1+b32*w2+b33*w3"}, "s": {"group": "Ungrouped variables", "name": "s", "templateType": "anything", "description": "", "definition": "random(4..6)"}, "p2": {"group": "Ungrouped variables", "name": "p2", "templateType": "anything", "description": "", "definition": "a21*v1+a22*v2+a23*v3"}, "p": {"group": "Ungrouped variables", "name": "p", "templateType": "anything", "description": "", "definition": "n+random(0,z)"}, "a31": {"group": "Ungrouped variables", "name": "a31", "templateType": "anything", "description": "", "definition": "random(1..3)"}, "s6": {"group": "Ungrouped variables", "name": "s6", "templateType": "anything", "description": "", "definition": "if(r=3,0.5,-0.5)"}, "ba13": {"group": "Ungrouped variables", "name": "ba13", "templateType": "anything", "description": "", "definition": "b11*a13+b12*a23+b13*a33"}, "mae": {"group": "Ungrouped variables", "name": "mae", "templateType": "anything", "description": "", "definition": "matrix(repeat(repeat(random(-2..9),s),r))"}, "ab23": {"group": "Ungrouped variables", "name": "ab23", "templateType": "anything", "description": "", "definition": "a21*b13+a22*b23+a23*b33"}, "s9": {"group": "Ungrouped variables", "name": "s9", "templateType": "anything", "description": "", "definition": "if(w=3,0.5,-0.5)"}, "x": {"group": "Ungrouped variables", "name": "x", "templateType": "anything", "description": "", "definition": "u+random(0,z)"}, "b12": {"group": "Ungrouped variables", "name": "b12", "templateType": "anything", "description": "", "definition": "random(0,1)"}, "ab12": {"group": "Ungrouped variables", "name": "ab12", "templateType": "anything", "description": "", "definition": "a11*b12+a12*b22+a13*b32"}, "w2": {"group": "Ungrouped variables", "name": "w2", "templateType": "anything", "description": "", "definition": "random(-4..4)"}, "a13": {"group": "Ungrouped variables", "name": "a13", "templateType": "anything", "description": "", "definition": "random(1..2)"}, "ab32": {"group": "Ungrouped variables", "name": "ab32", "templateType": "anything", "description": "", "definition": "a31*b12+a32*b22+a33*b32"}, "a23": {"group": "Ungrouped variables", "name": "a23", "templateType": "anything", "description": "", "definition": "random(-2..2)"}, "c12": {"group": "Ungrouped variables", "name": "c12", "templateType": "anything", "description": "", "definition": "random(1..3)"}, "b11": {"group": "Ungrouped variables", "name": "b11", "templateType": "anything", "description": "", "definition": "random(0,1)"}, "q2": {"group": "Ungrouped variables", "name": "q2", "templateType": "anything", "description": "", "definition": "b21*w1+b22*w2+b23*w3"}, "n": {"group": "Ungrouped variables", "name": "n", "templateType": "anything", "description": "", "definition": "random(3..6 except m)"}, "a11": {"group": "Ungrouped variables", "name": "a11", "templateType": "anything", "description": "", "definition": "random(1..4)"}, "a33": {"group": "Ungrouped variables", "name": "a33", "templateType": "anything", "description": "", "definition": "random(1..4)"}, "v2": {"group": "Ungrouped variables", "name": "v2", "templateType": "anything", "description": "", "definition": "random(1..4)"}, "p1": {"group": "Ungrouped variables", "name": "p1", "templateType": "anything", "description": "", "definition": "a11*v1+a12*v2+a13*v3"}, "v": {"group": "Ungrouped variables", "name": "v", "templateType": "anything", "description": "", "definition": "[[s1,-s1],[s2,-s2],[s3,-s3],[s4,-s4],[s5,-s5],[s6,-s6],[s7,-s7],[s8,-s8],[s9,-s9],[s10,-s10]]"}, "b22": {"group": "Ungrouped variables", "name": "b22", "templateType": "anything", "description": "", "definition": "random(-4,-3,-2,-1,1,2,3,4)"}}, "tags": [], "preamble": {"js": "", "css": ""}, "parts": [{"adaptiveMarkingPenalty": 0, "marks": 0, "customMarkingAlgorithm": "", "showFeedbackIcon": true, "variableReplacements": [], "type": "gapfill", "extendBaseMarkingAlgorithm": true, "unitTests": [], "gaps": [{"adaptiveMarkingPenalty": 0, "marks": 1, "correctAnswer": "matrix([[p1],[p2],[p3]])", "customMarkingAlgorithm": "", "showFeedbackIcon": true, "variableReplacements": [], "numRows": "3", "type": "matrix", "correctAnswerFractions": false, "variableReplacementStrategy": "originalfirst", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "allowResize": false, "useCustomName": false, "numColumns": 1, "scripts": {}, "tolerance": 0, "allowFractions": false, "markPerCell": false, "customName": ""}, {"adaptiveMarkingPenalty": 0, "marks": 1, "correctAnswer": "matrix([[q1],[q2],[q3]])", "customMarkingAlgorithm": "", "showFeedbackIcon": true, "variableReplacements": [], "numRows": "3", "type": "matrix", "correctAnswerFractions": false, "variableReplacementStrategy": "originalfirst", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "allowResize": false, "useCustomName": false, "numColumns": 1, "scripts": {}, "tolerance": 0, "allowFractions": false, "markPerCell": false, "customName": ""}, {"adaptiveMarkingPenalty": 0, "marks": 1, "correctAnswer": "matrix([\n [ba11,ba12,ba13],\n [ba21,ba22,ba23],\n [ba31,ba32,ba33]\n])", "customMarkingAlgorithm": "", "showFeedbackIcon": true, "variableReplacements": [], "numRows": "3", "type": "matrix", "correctAnswerFractions": false, "variableReplacementStrategy": "originalfirst", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "allowResize": false, "useCustomName": false, "numColumns": "3", "scripts": {}, "tolerance": 0, "allowFractions": false, "markPerCell": false, "customName": ""}, {"adaptiveMarkingPenalty": 0, "marks": 1, "correctAnswer": "matrix([\n [ab11,ab12,ab13],\n [ab21,ab22,ab23],\n [ab31,ab32,ab33]\n])", "customMarkingAlgorithm": "", "showFeedbackIcon": true, "variableReplacements": [], "numRows": "3", "type": "matrix", "correctAnswerFractions": false, "variableReplacementStrategy": "originalfirst", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "allowResize": false, "useCustomName": false, "numColumns": "3", "scripts": {}, "tolerance": 0, "allowFractions": false, "markPerCell": false, "customName": ""}], "showCorrectAnswer": true, "customName": "", "sortAnswers": false, "useCustomName": false, "scripts": {}, "prompt": "

Let

\n

\\[A = \\left(\\begin{array}{rrr} \\var{a11} & \\var{a12} & \\var{a13}\\\\ \\var{a21} & \\var{a22} & \\var{a23}\\\\ \\var{a31} & \\var{a32} & \\var{a33}\\\\ \\end{array}\\right),\\;\\;\\;\\; B= \\left(\\begin{array}{rrr} \\var{b11} & \\var{b12} & \\var{b13}\\\\ \\var{b21} & \\var{b22} & \\var{b23}\\\\ \\var{b31} & \\var{b32} & \\var{b33}\\\\ \\end{array}\\right),\\;\\;\\;\\; v= \\left(\\begin{array}{r} \\var{v1}\\\\ \\var{v2} \\\\ \\var{v3} \\end{array}\\right),\\;\\;\\;\\; w= \\left(\\begin{array}{r} \\var{w1}\\\\ \\var{w2} \\\\ \\var{w3} \\end{array}\\right)\\]

\n

Find the following products:

\n

$Av = $ [[0]]

\n

$Bw = $ [[1]]

\n

$BA = $ [[2]]

\n

$AB = $ [[3]]

", "variableReplacementStrategy": "originalfirst"}, {"adaptiveMarkingPenalty": 0, "marks": 0, "customMarkingAlgorithm": "", "showFeedbackIcon": true, "variableReplacements": [], "type": "gapfill", "extendBaseMarkingAlgorithm": true, "unitTests": [], "gaps": [{"showFeedbackIcon": true, "type": "m_n_x", "showCellAnswerState": true, "extendBaseMarkingAlgorithm": true, "maxMarks": 0, "minMarks": 0, "displayType": "radiogroup", "customName": "", "shuffleChoices": true, "scripts": {}, "customMarkingAlgorithm": "", "matrix": "v", "adaptiveMarkingPenalty": 0, "marks": 0, "choices": ["

$CD$

", "

$DC$

", "

$EF$

", "

$FE$

", "

$BC$

", "

$AE$

", "

$GH$

", "

$HE$

", "

$AG$

", "

$GB$

"], "variableReplacementStrategy": "originalfirst", "minAnswers": 0, "variableReplacements": [], "unitTests": [], "warningType": "none", "maxAnswers": 0, "useCustomName": false, "showCorrectAnswer": true, "shuffleAnswers": false, "answers": ["Can be calculated", "Cannot be calculated"], "layout": {"expression": ""}}], "showCorrectAnswer": true, "customName": "", "sortAnswers": false, "useCustomName": false, "scripts": {}, "prompt": "

Consider the following matrices together with the matrices from the first part of the question.

\n

\\[\\begin{eqnarray}&C=& \\var{mac},\\;\\;\\;\\; &D=& \\var{mad},\\;\\;\\; \\;&E= &\\var{mae}\\\\&F=& \\left(\\begin{array}{rr} \\var{w1} & \\var{a12}\\\\ \\var{w2} & \\var{b23} \\\\ \\var{w3} & \\var{w2} \\\\\\var{v1} & \\var{b12}\\\\ 0 & \\var{-w2} \\end{array}\\right),\\;\\;\\;\\;&G=&\\var{mag},\\;\\;\\;\\;&H=&\\var{mah} \\end{eqnarray}\\]

\n

Which of the following products of matrices can be calculated?

\n

[[0]]

\n

Please note that for every correct answer you get 0.5 marks and for every incorrect answer 0.5 is taken away. The minimum mark you can get is 0.

", "variableReplacementStrategy": "originalfirst"}], "statement": "\n

Answer the following questions on matrices.

\n

 

\n ", "contributors": [{"name": "Bill Foster", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/6/"}, {"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}, {"name": "Timur Zaripov", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/3272/"}]}]}], "contributors": [{"name": "Bill Foster", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/6/"}, {"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}, {"name": "Timur Zaripov", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/3272/"}]}