Question

The HCF and the LCM of 12, 21, 15 respectively are ______.

Options

• 3, 140

• 12, 420

• 3, 420

• 420, 3

Answer 1

The HCF and the LCM of 12, 21, 15 respectively are 3, 420.

Explanation:

12 = 2 × 2 × 3

21 = 3 × 7

And 15 = 3 × 5

∴ HCF = 3

And LCM = 2 × 2 × 3 × 5 × 7 = 420