The numbers less than 696 and are squares of certain numbers are 676, 625.The least number that should be subtracted from 696 to make it perfect square = 696 - 676 = 20.
LCM of 10, 15, 25 = 150When we drive 2641 by 150 the remainder is 91.But the remainder should be 7.So, the number to be subtracted from 2641 is 91 - 7 = 84.