Question

Find the least square number which is exactly divisible by each of the numbers 6, 9, 15 and 20.

Answer 1

L.C.M. of 6, 9, 15 and 20

$=2\times 3\times 5\times 2\times 3=180$
Now, $180=\overline{2\times 2}\times \overline{3\times 3}\times 5$
To make it a perfect square, it must be multiplied by 5
$\therefore$ Product= $180\times 5=900$ Hence, the least square number= 900