What is the least square number exactly divisible by each of the number 4,6and10?

There is nothing but to write a list of square numbers and evaluate each one. Only numbers ending in 0 qualify. Only numbers smaller than 57,600 need to be considered. Divide that by 4 and you get 14,400 which is 120 squared. Do it again and you get 3600 which is 60 squared. Do it again and you get 900 which is 30 squared. Do it again and you get 225 which does not qualify. So the answer is 900 (I think).