Question

In a school there are 20 teachers who teach Mathematics or physics of these 12 the teach
Mathematics & 4 teach both physics & Mathemates
Find how many teach physics ? (this is sets chapter)​

Answer 1

Answer:

4 teacher teaches

Step-by-step explanation:

20 teachers

mathematics=12 teachers

physics= 4

both teacher teaches both the subject=?=x

suppose .

Let both teacher be 2x

12-4=2x

8=2x

8/2=x

4=x

i.e x=4 (ans)

Answer 2

n(PuM) = 20

n(M)=12

n(PnM)=4

We know that

n(PuM)=n(P)+n(M)-n(PnM)

n(P)=n(PuM)-n(M)+n(PnM)

n(P)=20-12+4

n(P)=12