Question

Find the least square number which is exactly divisible by each of the numbers 8, 12, 15 and 20.

Answer 1

The smallest number divisible by each of these numbers is their L.C.M.
L.C.M. of 8, 12, 15, 20 = 120

Resolving into prime factors:
$120=2\times 2\times 2\times 3\times 5$

To make this into a perfect square, we need to multiply the number with $2\times 3\times 5=30$.

Required number = $120\times 30=3600$