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 i-th draw is a white ball, green ball, and blue ball, respectively. If P(W₁ ∩ G₂ ∩ B₃) = 2/(5N) and P(B₃ | W₁ ∩ G₂) = 2/9, then N equals ________.