SOLUTION: Question : Out of 100 students, two sections of 40 and 60 are to be formed. If you and your friend are among the 100 students, what is the probability that (i) you both will enter

Algebra ->  Probability-and-statistics -> SOLUTION: Question : Out of 100 students, two sections of 40 and 60 are to be formed. If you and your friend are among the 100 students, what is the probability that (i) you both will enter       Log On


   

Question 252557: Question : Out of 100 students, two sections of 40 and 60 are to be formed. If you and your friend are among the 100 students, what is the probability that (i) you both will enter the same section? (ii) you both will enter different sections?
Could you please help and oblige by giving a quick reply.
Answer by drk(1908) About Me  (Show Source):
You can put this solution on YOUR website!
We have a combination problem.
(i) you both will enter the same section?
You want to be with your friend in the 40 group OR the 60 group. Here is the probability:
(40C2*60C0 + 40C0*60C2) / (100C2) = .5151
(ii) you both will enter different sections?
(40C1*60C1 + 40C1*60C1) / (100C2) = .0404
we add another because you could be in the 40 or in the 60 group separated from friend.