the boys of a school can be arranged in 12,15 and 18 equals rows and also in to a solid square what is the least number of boys that the school can have.(hint find the LCM)
12 = 2^2 * 3
15 = 3*5
18 = 2*3^2
The smallest number which is a multiple of all of those must contain the highest power of each of the listed primes. So, that will be
2^2 * 3^2 * 5 = 180
But, we also want our number to be a perfect square, so we need to have 5^2 in the product.
So, 180*5 = 900 is such a square