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Maths

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Multiple-choice questions in a test are graded by adding 2 marks for each correct
response and subtracting 1 mark for each incorrect response (including no response).
Rory and Jenny answered all the multiple-choice questions, with Rory scoring 27 and
Jenny scoring 42. Rory answered 19 questions correctly.
a How many multiple-choice questions were there?
b How many more questions than Rory did Jenny answer correctly?

  • Maths - ,

    i don't care / know

  • Maths - ,

    a.Rory
    (19 correct ans X 2) 38
    Rory's score -27
    equals (incorrect ans)11 pts deducted

    therefore
    19 correct + 11 incorrect = 30 questions

    b.jenny
    Let x= correct answers
    y= incorrect answers

    equations:
    2x-y=42 eq1(which is the score of jenny)
    x+y=30 eq2(total no. of items)

    use elimination method
    then:
    3x=72
    divided both sides by 3
    x=24

    substituting to eq.1
    2x-y=42
    2(24)-y=42
    48-y=42
    y=48-42
    y=6
    or substituting to eq.2
    x+y=30
    24+y=30
    y=30-24
    y=6

    therefore
    jenny got 24 correct answers and 6 incorrect answers.

  • Maths - ,

    Answer for Jenny bought a gallon of orange juice. The recipe for punch calls for 2 quarts of juice. How many quarts will she have left over to drink at breakfast.

  • Maths - ,

    Screw you!!!

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