UPSC Prelims 2026 · CSAT Paper 2 · Set DMathematicsQ 18 / 80

UPSC Prelims 2026 CSAT Paper 2 — Question 18

Question

In an objective type question paper, 5 marks are awarded for a correct answer and 2 marks are deducted for a wrong answer. A student attempted all the questions and got a score of 69. Had he been awarded 4 marks for a correct answer and 1 mark deducted for a wrong answer, he would have scored 84. How many questions were there in the question paper?

(a)99
(b)81
(c)84
(d)79

UnlockIAS answer: (b)81

Solution

5c − 2w = 69 and 4c − w = 84. Solving gives c = 33, w = 48, so the total number of questions is 33 + 48 = 81.

UnlockIAS expert key, prepared 24 May 2026 and cross-verified by re-deriving the answer — this is our key, not the official UPSC provisional key (awaited).

Section

Mathematics

Topic Reference

Numeracy — Linear equations

Official UPSC key still awaited

UPSC has announced (PIB Release 2262441, 18 May 2026) that the provisional answer key for CSE Prelims 2026 will be released “soon after Exam”. Until then, use the CSAT score calculator for your qualifying-status estimate, and join the per-question discussion below.

CSAT Score Calculator

Check your 33% qualifying status

Official Notification

PIB Release 2262441

Back to all 80 CSAT questions