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What sentence represent the number of poins in the problem below

What sentence represent the number of poins in the problem below-example-1
User Lonelymo
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1 Answer

15 votes
15 votes

hello

to solve this question, we can write out two sets of equation and solve them

let the short answers be represented by x

let the multiple-choice questions be represented by y

we know that the test has 60 points

multiple-choice carries 2 points

short answers carries 5 points


2x+5y=60

now we have a total of 15 questions which comprises of multiple-choice questions and short answers


x+y=15

now we have two set of equations which are


\begin{gathered} 2x+5y=60\ldots\text{equ}1 \\ x+y=15\ldots\text{equ}2 \end{gathered}

now let's solve for x and y

from equation 2, let's make x the subject of formula


\begin{gathered} x+y=15 \\ x=15-y\ldots\text{equ}3 \end{gathered}

put equation 3 into equation 1


\begin{gathered} 2x+5y=60 \\ x=15-y \\ 2(15-y)+5y=60 \\ 30-2y+5y=60 \\ 30+3y=60 \\ \text{collect like terms} \\ 3y=60-30 \\ 3y=30 \\ \text{divide both sides by the coeffiecient of y} \\ (3y)/(3)=(30)/(3) \\ y=10 \end{gathered}

now we know the value of y which is the number of multiple-choice question. we can use this information to find the number of short answer through either equation 1 or 2

from equation 2


\begin{gathered} x+y=15 \\ y=10 \\ x+10=15 \\ \text{collect like terms} \\ x=15-10 \\ x=5 \end{gathered}

from the calculations above, the number of short answers is equal to 5 and multiple-choice questions is equal to 10.

The answer to this question is option C

User Cynthia
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2.9k points