UPSC Prelims 2026 · CSAT Paper 2 · Set DMathematicsQ 40 / 80

UPSC Prelims 2026 CSAT Paper 2 — Question 40

Question

If x and y are two digits and the number 4x5y790 is divisible by 11, then what is the remainder, if x + y is divided by 11?

(a)1
(b)3
(c)5
(d)7

UnlockIAS answer: (d)7

Solution

Alternating digit sum = 4 − x + 5 − y + 7 − 9 + 0 = 7 − (x + y), which must be a multiple of 11, so x + y = 7 (or 18). In either case (x + y) mod 11 = 7.

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 — Divisibility by 11

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