UPSC Prelims 2026 · CSAT Paper 2 · Set DMathematicsQ 37 / 80

UPSC Prelims 2026 CSAT Paper 2 — Question 37

Question

In a sequence of numbers, each number other than the first two is the sum of the two immediately preceding numbers from it. If the first two numbers in the sequence are 4 and 7, then the sixth number is

(a)29
(b)37
(c)43
(d)47

UnlockIAS answer: (d)47

Solution

The sequence is 4, 7, 11, 18, 29, 47. The sixth term is 47.

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 — Number series

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.

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Official Notification

PIB Release 2262441

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