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CSAT 2026 paper

UPSC CSE CSAT 2026 · Paper II (CSAT) · Question 19 · Number system

यदि 10ᵐ × 1000 × n = 75²⁵ × 25³² × 32⁷⁵ है, जहाँ n, 10 से विभाज्य नहीं है, तो m का मान क्या है?

UPSC Civil Services (Preliminary) Examination 2026, General Studies Paper II (CSAT), Question 19 — Number system.

CSAT 2026 · Q19

Number system Easy Provisional key

यदि 10ᵐ × 1000 × n = 75²⁵ × 25³² × 32⁷⁵ है, जहाँ n, 10 से विभाज्य नहीं है, तो m का मान क्या है?

Read this question in English

If 10ᵐ × 1000 × n = 75²⁵ × 25³² × 32⁷⁵, where n is not divisible by 10, then the value of m is

(a) 101 · (b) 111 · (c) 121 · (d) 131

उत्तर और व्याख्या · explanation in English

Answer: (b) 111

Break the right side into primes: 2³⁷⁵ × 3²⁵ × 5¹¹⁴. The number of 10s is the smaller of the powers of 2 and 5, i.e., 114, and n must hold none of them, so m + 3 = 114.

  1. 75²⁵ = (3 × 5²)²⁵ = 3²⁵ × 5⁵⁰.
  2. 25³² = 5⁶⁴.
  3. 32⁷⁵ = (2⁵)⁷⁵ = 2³⁷⁵.
  4. Right side = 2³⁷⁵ × 3²⁵ × 5¹¹⁴, which contains exactly 10¹¹⁴ (limited by the 5s).
  5. n = 2²⁶¹ × 3²⁵ is not divisible by 10, so 10ᵐ × 10³ = 10¹¹⁴ and m = 111.

Remember · Powers of 10 in a product = min(power of 2, power of 5). Count both, take the smaller.

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

Cite this question: UPSC CSE CSAT 2026, Q19 — minimalistias.com/pyqs/csat/2026/q19

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