Question

Find the largest 3 digit common multiple of 20 and 35.
1. 980
2. 140
3. 840
4. 990

Answer 1

Correct Answer - Option 1 : 980

Given:

Numbers are 20 & 35.

Concept used:

Firstly find LCM of (20, 35), then find its largest multiple of 3 digits.

Explanation:

20 = 2² × 5¹

35 = 5¹ × 7¹

⇒ LCM of (20, 35) = 2² × 5¹ × 7¹

⇒ 140

⇒ 140 × 7

⇒ 980

∴ The largest 3 digit common multiple of 20 and 35 is 980.