Example 24 In a school there are 20 teachers who teach mathematics or physil these, 12 teach mathematics and 4 teach both physics and mathematics. How Ex
teach physics ?

The number of teachers who teach  physics   n(P) = 12

Step-by-step explanation:

Step(i):-

Given that the number of teachers who teach mathematics or physics

n(MUP) = 20

Given that  the number of teachers who teach mathematics

n(M) = 12

Given that the number of teachers who teach both mathematics and physics

n(M∩P) = 4

Step(ii):-

By using   n(A∪B) = n(A) + n(B) - n(A∩B)

                n(M∪P) = n(M) +n(P) - n(M∩P)

                20         = 12 + n(P) - 4

               20 -12 +4 = n(P)

                    n(P) = 12

Final -

The number of teachers who teach  physics   n(P) = 12

answer is 144

step-by-step explanation:

question 1 is 8, question 2 is 9, question 3 is 24

step-by-step explanation:

now, the numbers they give you at the top are the key. from there, you just have to plug and chug! let's try 1, 2, and 3!

key: a=3, b=5, c=6

1. a+5

remember, a=3, so we plug that in to get 3+5=8

2. 15-c

c=6, so we plug that in to get 15-6=9

3. 4b

b=6, so we plug it in to get 4*6=24

time to try the rest on your own! if you put the answers below in a comment, i'll check them for you!