Given:
4 red marble
3 blue marble
2 yellow marble
1 green marble
Total marble = 4 + 3 + 2 + 1 = 10 marble
Probability is given by



If the yellow ball is drawn again, the total number of the yellow ball will be reduced to 1, and the total number of marble is given to be 9
Then the probability will be

Then the probability that both are yellow are

The probability that both are yellow = 1/45