In an exam, a candidate attempts 20 questions and scores 72 marks. If

In an exam, a candidate attempts 20 questions and scores 72 marks. If 5 marks are awarded for each correct answer and 2 marks are deducted for each wrong answer, then how many questions were answered correctly by him ?

[amp_mcq option1=”18″ option2=”17″ option3=”16″ option4=”15″ correct=”option3″]

This question was previously asked in
UPSC CAPF – 2020
16
This problem can be solved by setting up a system of two linear equations based on the given information about the number of questions attempted and the total score.
Let ‘c’ be the number of questions answered correctly and ‘w’ be the number of questions answered incorrectly.
Total questions attempted: c + w = 20
Total score: 5c – 2w = 72
From the first equation, w = 20 – c. Substitute this into the second equation:
5c – 2(20 – c) = 72
5c – 40 + 2c = 72
7c = 72 + 40
7c = 112
c = 112 / 7
c = 16
So, the candidate answered 16 questions correctly.