Find the smallest square number which is divisible by each of the numbers 4, 9, and 10.

4 = 2 × 2
9 = 3 × 3
10 = 2 × 5
L.C.M = 2² × 3² × 5 = 180
But 180 is not a perfect square. Multiply 180 with 5 to get pairs.
Required no. = 180 × 5 = 900