statistics /pure maths
posted by gbafa .
A box contains N identical balls of which 4 are Red, 3 are Green and the rest are White . If 3 balls are drawn at random one after the other without replacement.the probability that all 3 balls are Whit is 1/22.
1.Find the number of identical balls in the container .
2.Find the probability that the first two balls drawn are Green and the third is a different colour.