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UPSC CSE CSAT 2020 · Question 48 · Logical & analytical reasoning

The letters from A to Z are numbered from 1 to 26 respectively. If GHI = 1578 and DEF = 912, then…

CSAT 2020 · Q48

Logical & analytical reasoning Medium

The letters from A to Z are numbered from 1 to 26 respectively. If GHI = 1578 and DEF = 912, then what is ABC equal to?

Answer & explanation

Answer: (d) 246

G, H, I are 7, 8, 9 and 789 × 2 = 1578; D, E, F are 4, 5, 6 and 456 × 2 = 912. So each code is the three letter numbers written together and doubled: ABC = 123 × 2 = 246.

  1. GHI → 7, 8, 9 → 789; 789 × 2 = 1578.
  2. DEF → 4, 5, 6 → 456; 456 × 2 = 912.
  3. ABC → 1, 2, 3 → 123; 123 × 2 = 246.

Remember · In number codes, write the letter positions side by side first and look for a single operation that gives the code.

Question and answer: UPSC's official GS Paper II (2020, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·

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