Sets-Relations-And-Functions Question 127
Question: 20 teachers of a school either teach mathematics or physics. 12 of them teach mathematics while 4 teach both the subjects. Then the number of teachers teaching physics only is
Options:
A) 12
B) 8
C) 16
D) None of these
Correct Answer: BShow Answer
Answer:
Solution:
Number of teachers in Maths $ n(P\cup M)=n(P)+n(M)-n(P\cap M) $
$ 20=n(P)+12-4\Rightarrow n(P)=12 $ Only Physic?s teacher = 8