Example 24 In a school there are 20 teachers who teach mathematics or physil these, 12 teach mathematics and 4 teach both physics and mathematics. How Ex
teach physics ?

The number of teachers who teach  physics   n(P) = 12

Step-by-step explanation:

Step(i):-

Given that the number of teachers who teach mathematics or physics

n(MUP) = 20

Given that  the number of teachers who teach mathematics

n(M) = 12

Given that the number of teachers who teach both mathematics and physics

n(M∩P) = 4

Step(ii):-

By using   n(A∪B) = n(A) + n(B) - n(A∩B)

                n(M∪P) = n(M) +n(P) - n(M∩P)

                20         = 12 + n(P) - 4

               20 -12 +4 = n(P)

                    n(P) = 12

Final -

The number of teachers who teach  physics   n(P) = 12

f is the midpoint of