Total balls = 5 + 4 + 4 = 13∴ n(S) = 13C3 = 2862 blue balls can be selected from 4 balls in 4C2 = 6 ways and the remaining one ball is to be selected from 9 balls in 9C1 = 9 ways ∴ n(E) = 6 x 9∴ P(E) = 6 x 9/286 = 27/143
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.
132 = 11 * 3 * 4Clearly, 968 is not divisible by 3None of 462 and 2178 is divisible by 4And, 5284 is not divisible by 11Each one of the remaining four numbers is divisible by each one of 4, 3 and 11.So, there are 4 such numbers.