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Railways PYQCBT 1 2016

RRB NTPC · Question 34

Find the H.C.F. and L.C.M. of 20 and 28.

  1. 20, 280

  2. 5, 280

  3. 10, 140

  4. 4, 140

Show answer & explanation

Answer: (D) 4, 140

Explanation

20 = 2² × 5 and 28 = 2² × 7. HCF = 2² = 4, and LCM = 2² × 5 × 7 = 140. (Check: HCF × LCM = 4 × 140 = 560 = 20 × 28.)