In a group of 120 persons there are 70 Bengalis, 35 Gujaratis.
Further, 70 persons in the group and Muslims and the remaining
Hindus. Then the number of Bengali Muslims in the group is
(a) 30 or more
(b) Exactly 20
(c)Between 15 and 25
(d) Between 20 and 25

Dear student, 
your question is not clear and seems to be incomplete as information about only 105 persons (70 Bengalis and 35 Gujarat is) is given out of 120 persons. So i have solved this question according to my assumptio, if what I have assumed is not your question then please repost it in a seperate thread. 

Regards