in school there are 30 teacher who teach maths or physical of there ,1

1.	in school there are 30 teacher who teach maths or physical of there ,18 teach maths and 6 teach , both physical and maths . how many teach physics only
Answer» Answer: Number of TEACHERS who teach math or physics =N(M∪P)=20 Number of teachers who teach math = n(M)=12 Number of teachers who teach math and physics =n(M∩P)=4 Find : Number of teachers who teach physics =n(P)=? SOLUTION : n(M∪P)=n(m)+n(P)−n(M∩P) 20=12+n(P)−4 20−12+4=n(P) n(P)=12 hence 12 teacher teach the physics

in school there are 30 teacher who teach maths or physical of there ,18 teach maths and 6 teach , both physical and maths . how many teach physics only

Answer»

Answer:

Number of TEACHERS who teach math or physics =N(M∪P)=20

Number of teachers who teach math = n(M)=12

Number of teachers who teach math and physics =n(M∩P)=4

Find : Number of teachers who teach physics =n(P)=?

n(M∪P)=n(m)+n(P)−n(M∩P)

20=12+n(P)−4

20−12+4=n(P)

n(P)=12

hence 12 teacher teach the physics