Sets Relations And Functions Question 25
In a school, there are 20 teachers who teach mathematics or physics. Of these, 12 teach mathematics and 4 teach both maths and physics. Then the number of teachers teaching only physics are
Options:
A) 4
B) 12
C) 8
D) 16
Show Answer
Answer:
Correct Answer: B
Solution:
- [b]
We know that ( n(M \cup P) = n(M) + n(P) - n(M \cap P) ).
Given: $ 20 = 12 + n(P) - 4 $
Solving for ( n(P) ):
$ 20 = 12 + n(P) - 4 $
$ 20 = 8 + n(P) $
$ n(P) = 12 $
Thus, $ n(P) = 12 $
Hence, 12 teachers teach physics.
BETA
