Question

In a class of 30 students, 10 take Mathematics, 15 take Physics, and 10 take
neither. The number of students who take both mathematics and physics is
C3​

Answer 1

Answer:

n(A∪B)=n(A)+n(B)−n(A∩B)

20=10+15−n(A∩B)orn(A∩B)=5