Question

2. All the students in SS3 of a named school take either Mathematics (M), or Physics (P) or Chemistry (C). 40 take Mathematics, 42 take physics, 38 take Chemistry, 20 take Mathematics and Physics, 28 take Physics and Chemistry while 25 take mathematics and chemistry.
How many take
(a) All the three subject: 120
(b) Mathematics, but neither Physics nor Chemistry
(c) Physics, but neither Mathematics nor Chemist