What is the smallest positive integer that is divisible by all 25, 30 and 40?
Show answer & explanation
Correct answer: D
Explanation
This is a question of LCM (least common multiple).
25 = 5²
30 = 2 × 3 × 5
40 = 2³ × 5
In LCM take the maximum power of each prime factor:
LCM=23×3×52
=8×3×25=600