Question

In a school, there are 30 teachers who teach Mathematics or Physics. Of these, 18 teach Mathematics and 6 teach both Physics and Mathematics. How many teach Physics only?​

Answer 1

let p and m be the no. of teacher who teach physics and mathematics

Here,

n(u) = 30

no.(m)=18

n(pnm) =6

no.(p)=?

Now

no.(p) = n(m)-n(pnm)

= 18-6

= 12

Hence,

No. of teacher who teach physics are 12

Answer 2

Answer:

$6$ teach  Physics only

Step-by-step explanation:

Given:

there are $30$ teachers who teach Mathematics or Physics.

$18$ teach Mathematics

$6$ teach both Physics and Mathematics

As the total teacher are $30$

In that $18$ teach maths so the remaining teacher are

$30-18=12$

In that $6$ teach both Physics and Mathematics so the remaining will be the teachers who teach physics only so we get as

$12-6=6$