2025 CSAT, all questions
UPSC Prelims 2025 · CSAT
Question 20: Basic Numeracy
What is the unit digit in the multiplication of 1 × 3 × 5 × 7 × 9 × . . . × 999 ?
a1
b3
c5
d9
UPSC's 2025 key was reported published in May 2026, but no file was found on upsc.gov.in or in the Wayback Machine. The 2025 papers can be browsed, not scored.
Source: UPSC, Civil Services (Preliminary) Examination 2025, General Studies Paper II (CSAT), Series A. The paper on upsc.gov.in.