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
Let the no. be xTherefore 68x / 100 - 35x / 100 = 1216 Therefore x = 1216 x 100 / 33Therefore 28% of x = 28x / 100 = 1216 x 100 / 33 x 28 / 100= 1216 x 100 x 28 / 33 x 1/100 = 1031.75