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$A = \\{$ {firstval} or {secondval} appears $\\}$

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$C = \\{$ {oddevenstring} number appears$\\}$

", "correctAnswerFraction": true, "customMarkingAlgorithm": "", "maxValue": "oddevenfreq", "scripts": {}, "extendBaseMarkingAlgorithm": true, "minValue": "oddevenfreq", "correctAnswerStyle": "plain", "type": "numberentry", "showCorrectAnswer": true, "mustBeReduced": false, "unitTests": [], "mustBeReducedPC": 0, "marks": 1, "showFeedbackIcon": true, "variableReplacementStrategy": "originalfirst"}], "rulesets": {}, "variablesTest": {"maxRuns": 100, "condition": ""}, "variables": {"n4": {"group": "Ungrouped variables", "templateType": "randrange", "definition": "random(14..20#1)", "description": "", "name": "n4"}, "n1": {"group": "Ungrouped variables", "templateType": "randrange", "definition": "random(14..20#1)", "description": "", "name": "n1"}, "firstval": {"group": "Ungrouped variables", "templateType": "randrange", "definition": "random(1..6#1)", "description": "", "name": "firstval"}, "oddevenfreq": {"group": "Ungrouped variables", "templateType": "anything", "definition": "if(oddeven,(n1+n3+n5)/100,(n2+n4+n6)/100)", "description": "", "name": "oddevenfreq"}, "secondval": {"group": "Ungrouped variables", "templateType": "anything", "definition": "random(secondvalset)", "description": "", "name": "secondval"}, "sol1": {"group": "Ungrouped variables", "templateType": "anything", "definition": "(value_list[firstval-1]+value_list[secondval-1])/100", "description": "", "name": "sol1"}, "n5": {"group": "Ungrouped variables", "templateType": "randrange", "definition": "random(14..20#1)", "description": "", "name": "n5"}, "value_list": {"group": "Ungrouped variables", "templateType": "anything", "definition": "[n1,n2,n3,n4,n5,n6]", "description": "", "name": "value_list"}, "n3": {"group": "Ungrouped variables", "templateType": "randrange", "definition": "random(14..20#1)", "description": "", "name": "n3"}, "secondvalset": {"group": "Ungrouped variables", "templateType": "anything", "definition": "list(set(1,2,3,4,5,6)-set(firstval))", "description": "", "name": "secondvalset"}, "oddeven": {"group": "Ungrouped variables", "templateType": "randrange", "definition": "random(0..1#1)", "description": "", "name": "oddeven"}, "n6": {"group": "Ungrouped variables", "templateType": "anything", "definition": "100-n1-n2-n3-n4-n5", "description": "", "name": "n6"}, "n2": {"group": "Ungrouped variables", "templateType": "randrange", "definition": "random(14..20#1)", "description": "", "name": "n2"}, "oddevenstring": {"group": "Ungrouped variables", "templateType": "anything", "definition": "if(oddeven,\"odd\",\"even\")", "description": "", "name": "oddevenstring"}}, "preamble": {"js": "", "css": ""}, "variable_groups": [], "ungrouped_variables": ["n1", "n2", "n3", "n4", "n5", "n6", "oddeven", "oddevenstring", "oddevenfreq", "secondvalset", "firstval", "secondval", "value_list", "sol1"], "metadata": {"description": "", "licence": "None specified"}, "functions": {}, "statement": "

A die is tossed $100$ times and the number appearing on the upper face recorded as follows:

\n

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Number$1$$2$$3$$4$$5$$6$
Frequency$\\var{n1}$$\\var{n2}$$\\var{n3}$$\\var{n4}$$\\var{n5}$$\\var{n6}$
\n

\n

Find the relative frequency of the following events:

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Find $A\\cup B$

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Find $B\\cap C$

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Find $\\Omega\\setminus B$

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Find $(\\bar{A}\\cup C)\\cap B$

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Let $\\Omega = \\var{O}$ and $A$, $B$ and $C$ be the events:

\n

$A=\\var{A}$, $B=\\var{B}$, $C=\\var{C}$

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Do not take mathematics

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Take mathematics or physics (or both)

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Take physics but not mathematics

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Take exactly one of the two subjects.

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Take neither mathematics nor physics.

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Among {total} A-Level students in a sixth form college, {maths} take mathematics, {physics} take physics and {both} take both mathematics and physics.

\n

\n

Find the number of students who:

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Two fair, standard dice are thrown and the sum of the two faces recorded.

\n

\n

Find the probabilities of the following:

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Sum is sumval or more

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Value to appear on 1 die

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$A = \\{$ two numbers are {equalstring} $\\}$

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$B=\\{$ sum is $\\var{sumval}$ or more $\\}$

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$C = \\{\\var{d}$ {appearstring} {firstsecondstring} $\\}$

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Total number of questions

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A student is to answer $\\var{n}$ out of $\\var{noqs}$ questions on an exam.

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Find the number of ways $n$ the student can choose the $\\var{n}$ questions.

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Find $n$ if the student must answer the first $\\var{firstn}$ questions.

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Suppose the exam is divided into $2$ parts.

\n\n

If the student has to answer $\\var{partan}$ questions from Part A and $\\var{partbn}$ questions from Part B, what is $n$ in this case?

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if anybody can drive;

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one of only $\\var{drivers}$ can drive.

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Find the number of ways $\\var{npeople}$ people can sit in a car with $\\var{npeople}$ seats

", "tags": [], "type": "question"}, {"name": "Probability7", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Edward Hall", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/1824/"}], "variables": {"odd": {"description": "", "group": "Ungrouped variables", "templateType": "anything", "definition": "random(0,1)", "name": "odd"}, "ans1": {"description": "", "group": "Ungrouped variables", "templateType": "anything", "definition": "(15-n)/15", "name": "ans1"}, "ans2": {"description": "", "group": "Ungrouped variables", "templateType": "anything", "definition": "length(filter(x>n,x,oddset))/length(oddset)", "name": "ans2"}, "n": {"description": "", "group": "Ungrouped variables", "templateType": "anything", "definition": "random(8,12)", "name": "n"}, "oddset": {"description": "", "group": "Ungrouped variables", "templateType": "anything", "definition": "if(odd,list(1..15#2),list(2..15#2))", "name": "oddset"}, "oddstring": {"description": "", "group": "Ungrouped variables", "templateType": "anything", "definition": "if(odd,\"odd\",\"even\")", "name": "oddstring"}}, "advice": "", "statement": "

A pool ball is drawn at random from a box containing $15$ pool balls numbered $1$ to $15$ and the number $n$ is recorded

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Find the probability $p$ that $n$ exceeds $\\var{n}$.

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If $n$ is {oddstring}, find the probability $p$ that $n$ exceeds $\\var{n}$.

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In a University, $\\var{fail_calc}\\%$ of students failed Calculus, $\\var{fail_lin}\\%$ of students failed Linear Algebra and $\\var{fail_both}\\%$ failed both Calculus and Linear Algebra. A student is selected at random.

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If the student failed Linear Algebra, what is the probability that they failed Calculus?

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If the student failed Calculus, what is the probability that they didn't fail Linear Algebra?

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What is the probability that the student failed neither Calculus nor Linear Algebra?

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Find the probability that the item is defective.

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If the item is defective, find the probability that the item was produced by machine {machine}

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Three machines $A$, $B$ and $C$ produce, respectively, $\\var{A}\\%$, $\\var{B}\\%$ and $\\var{C}\\%$ of the items in a factory. The percentage of defective items produced by the machines is, respectively, $\\var{percentA}\\%$, $\\var{percentB}\\%$ and $\\var{percentC}\\%$. An item from the factory is selected at random.

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Number blue balls

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no red/blue balls picked

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Number of red balls

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Number of balls selected

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A bag contains $\\var{M}$ red balls and $\\var{N}$ blue balls. A ball is selected at random from the bag, its colour noted, and it is replaced. This is performed $\\var{nopicked}$ times.

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What is the probability that {fewerstring} $\\var{noballs}$ {blueredstring} balls are picked? 

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What is the expectation of the number of {blueredstring} balls selected?

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What is the variance of the number of {blueredstring} balls selected?

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What is the standard deviation of the number of {blueredstring} balls selected?

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