Given:
Number of orange balls = 3
Number of yellow balls = 3
Number of red balls = 4
To find:
The probability of:
1) 2 orange balls
2) 2 yellow balls
3) 1 red and 1 yellow ball
Solution:
We know that,

The total number of balls is

Using the above formula, we get



The ball drawn first is replaced before the second is drawn. So, the probabilities remains unchanged.
1) The probability of getting the 2 orange balls is



Therefore the probability of getting the 2 orange balls is 0.09.
2) The probability of getting the 2 yellow balls is



Therefore the probability of getting the 2 yellow balls is 0.09.
3) The probability of getting the 1 red and 1 yellow ball is



Therefore the probability of getting the 1 red and 1 yellow ball is 0.12.