Question

In a school there are 20 teachers who teach mathametics or physics. of these,12 teach mathamatics and4 teach both physics andathamatics. how many teach physics?​

Answer 1

4 people teach physics

Answer 2

Answer:

12 teachers teach physics

Step-by-step explanation:

n(a or b)=n(a)+n(b)-n(a and b)

20 =12 +n(b)-4

n(b) = 20-12+4

= 12