From a group of 8 people, including george and nina, 3 people are to be selected at random to work on a certain project. what is the probability that 3 people selected will include george but not ninaa 5/56b 9/56c 15/56d 21/56e 25/56

 C.

Explanation:

Given : Total people = 8

Number of people are to be selected  = 3

The number of combinations of r things taken out of n things is given by :-

The total number of ways to select 3 people out of 8 is given by :-

If George is included , then one person is confirmed, so we need to selec only 2 people out of 7.

Also, Nina is not selected , so the total number of people left= 6

The total number of ways to select 2 people out of 6 that will include George but not Nina is given by :-

i.e. No. of favorable outcomes= 15

Now, the probability that 3 people selected will include George but not Nina :-

Hence, the required probability = C.