Multiple choice

What is the greatest number by which when 156,181 and 331 are divided, the remainder is 6 in each case?

  1. 26

  2. 17

  3. 25

  4. 13

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

If a number N leaves remainder 6 when dividing each number, then (N-6) must divide each of (156-6), (181-6), and (331-6) exactly. This gives us 150, 175, and 325. Factorizing: 150 = 2 × 3 × 5², 175 = 5² × 7, 325 = 5² × 13. The common factor is 5² = 25.