From a Group of 10 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 Nina
Options:
(A) 5/56
(B) 9/56
(C) 28/120
(D) 21/56
(E) 25/56 Now, let's think a bit. Some random thoughts:
Number of ways of selecting 3 people out of 10 people = 10C3
In the three members George will always be there in the team. At this step we have vacancy for 2 more members and 9 members are available. Lina cannot be there in the team. So 2 members have to be selected and the number of available members = 9 - Nina = 8
Number of ways to form a 3 member team that includes George and excludes Nina = 8C2
Probability = 8C2/10C3 = 28/120
The final answer: (C).