Given the following:
4 green marbles
3 white marbles
2 black marbles
Total marbles = 4 + 3 + 2
= 9
probability of picking first green =4/9
Probability of picking a green again = 4/9 (with replacement)
Therefore, the probability of getting a green and a green again is:
P = 4/9 x 4/9
p = 16/81
Therefore the probablity of getting a green and then a green again is = 16/81