Question

Find the greatest four digit perfect square number which is exactly divisible by 12,18 and30.​

Answer 1

hi

The 4 digit number should end with a 0 ( multiple of 10 ) if it should be divisible by 30.

If it is a perfect square, even its root should end with a 0 ( multiple of 10 ).

Let us start from the upperlimit :

100^2= 10000 ( which is 5 digit )

90^2 = 8100

8100 is divisible by 12, 18 and 30.

( L.C.M of 12,18,30 =180, 8100/180=45)

Therefore, 8100 is the highest four digit perfect square number which is divisible by 12,18 and 30.

(key - ''^'' refers to the power)

thnx

have a nice day

Answer 2

8100

Therefore, 8100 is the highest four digit perfect square number which is divisible by 12,18 and 30.