Question

a bag contains some balls of which 1/4 is black and 1/9 along with 1/4 are red and 7 times the square root are blue and the white balls are 56 . find total number of balls in bag

Answer 1

This is how I came up with 2/27. the probability of getting one red is 3/9 (nine is the total number of balls). The probability of getting a white ball is 2/9 (9 again because the ball is put back after each draw) so 3/9*2/9 + 6/81 = 2/27


according to Dookie (who is right) if they are asking for the balls to draw one of the the other, which they are (successive draws) you have to multiply 2/27 by 2 = 4/27.