Please help in answering the following question from GMATPrep Ques 1:
A certain one-day seminar consisted of a morning session and an afternoon session. If each of the 128 people attending the seminar attended at least one of the two sessions, how many of the people attended the morning session only.
1) 3/4 of the people attended both sessions
2) 7/8 of the people attended the after noon session

I chose ans C but that is wrong :--(

The answer is (B)

From (2) total no of participants attended afternoon session = (7/8)* 128 = 112. Out of 128, 112 attended afternoon session. Hence the no. of people who did not attend afternoon session or who attended morning session = 128-112 = 16. Sufficient

From (1) 3/4 of 128 = 96 people attended both the sessions. But we have no information about rest of the people.

Thanks "Guest".

I missed the keyword "only" in the end and made mistake.
Thanks for correct and clear answer!