In an exam, 1 Mark Is Awarded For Each Correct Answer And 1/2mark Reduced For Each Wrong Answer. Rita Answered 120 Questions And Got 90 Marks How Many Questions Did She Answer Correctly?

Given: In an exam, 1 Mark Is Awarded For Each Correct Answer And 1/2mark Reduced For Each Wrong Answer.

To find: We have to find the number of questions did Rita answered correctly.

Solution: 

Let number of question answered correctly by Rita = a

So, number of question answered incorrectly by Rita = 120 - a

Now,

$1\ \times \ a\ -\ \frac{1}{2} \ \times \ ( 120\ -\ a) \ =\ 90$

$\Longrightarrow \ a\ -\ 60\ +\ \frac{a}{2} \ =\ 90$

$\Longrightarrow \ \frac{3a}{2\ } \ =\ 90\ +\ 60\ =\ 150$

$\Longrightarrow \ a\ =\ \frac{300}{3} \ =\ 100$

Therefore,

Number of question answered correctly by Rita = a = 100

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Updated on: 10-Oct-2022

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