As we need to select 5 out of 40 so the denominator of this probability would be 40C5. if we randomly select one of the certain traits from 3 of them then they could be selected as 3C1 ways and we need to select the other 4 choices from the remaining 37 choices (as 3 have a certain trait, so excluding them from the group) as 37C4 ways. so the nominator would be (3C1) (37C4). so the answer would be E.
1 Like
Thanks