Question

A bag contains N balls out of which 3 balls are white, 6 balls are green, and the remaining balls are blue. Assume that the balls are identical otherwise. Three balls are drawn randomly one after the other without replacement. For i = 1, 2, 3, let Wi, Gi and Bi denote the events that the ball drawn in the ith draw is a white ball, green ball, and blue ball, respectively. If the probability $P(W_1∩G_2∩B_3)=\frac{2}{5N}$ and the conditional probability $P(B_3|W_1∩G_2)=\frac{2}{9}$, then N equals ________.

Answer 1

The correct answer is: 11.