Probability Practice Test 1

There are 4 identical white and 4 identical black balls and we have to select 3, which can be selected in the following pattern:i.e., in all 4 ways.It should be noted that the ways of selecting 3 white balls from 4 white balls is not equal to 4C3 since the white balls are identical, it is equal to 1. Similar is the cases for 2, 1, etc.
Now the number of ways of selecting 3 white balls = 1.
Hence, required probability =

1

4

.