SSC GD 2024 PYQ — Question 56

SSC GD Const (English) - 24 Feb 2024 - Shift 1 • Quantitative Aptitude • Q56

Find the HCF of 84, 126, and 168.

Show answer & explanation

Correct answer: D

Explanation

The correct answer is option 4 i.e. 42.

Prime factorization of 84:

⇒     84 = 22  × 3 × 7

 Prime factorization of 126:

⇒  126 = 2  × 32  × 7

Prime factorization of 168:

⇒   168 = 23 × 3 × 7

The common prime factors of 84, 126, and 168 are 2, 3, and 7 of the common prime factors.

Highest Common Factor= 2​1 × 31 × 71 = 2 × 3 × 7 = 42

The Highest Common Factor of 84, 126, and 168 is 42.