Question

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

Answer 1

First let us factorise the given numbers and see their powers.
8 = 2^3
12 = 2^2 x 3
15 = 3 x 5
20 = 2^2 x 5

So a number which is divisible by each of them should contain 

2^3 x 3 x 5

Now for it to be a perfect square, it should have even powers

Hence, 

2^4 x 3^2 x 5^2 is sufficient and least number which will satisfy all conditions.
3600 is the answer

Answer 2

hope it will help you