Question

If n( A ∩ B') = 2x+40, n(A ∩ B)= x+10 and n(B ∩ A' )= 60 -3x, Then find n(AUB).

Answer 1

hope this helps you....
regards nishita.

Answer 2

See attached for the following diagrams:  (1) A ∩ B (2) B ∩ A' (3) A ∩ B

We can observed that:

n(AUB) = n(A ∩ B') + n(B ∩ A')  + n(A ∩ B)

Find n(AUB) :

n(AUB)  =  (2x + 40) + (x + 10) + (60 - 3x)

n(AUB)  =  2x + 40 + x + 10 +  60 - 3x

n(AUB)  =  110

Answer: n(AUB) = 110