Private Benjamin is a member of a squad of 10 soldiers, which must volunteer 4 of its members for latrine duty. If the members of the latrine patrol are chosen randomly, what is the probability T that private Benjamin will be chosen for latrine duty?  Choose the correct choice from the following choices.
A) 1/10  B) 1/5  C) 2/5  D) 3/5  E) 4/5
Easier way : Desired probability = 1- 'excluded' probability   In this case, Excluded probability = probability of Benjamin not being a part of the 4 volunteers. We can choose 4 out of 9 remaining soldiers in 9C4 ways. total ways possible = 10C4.   Thus excluded probability = 9C4/10C4 = 3/5   Thus, the desired probability T= 1- 3/5 = 2/5. Thus 2/5 is the correct answer.
<result>C</result>
Private Benjamin is a member of a squad of 10 soldiers, which must volunteer 4 of its members for latrine duty. If the members of the latrine patrol are chosen randomly, what is the probability T that private Benjamin will be chosen for latrine duty?