Question

(b) If n (U) = 200,n (A) = 120,
(2)
n (B) = 50, n(B)=30
, then find n (A'nB')​

Answer 1

A and B are the subsets.

n (U) = 200

n ( A ) = 120

n ( B ) = 50

As we know the formula for "Set Rules ":

n ( A U B ) = n ( A ) + n ( B ) - n ( A n B )

n ( A U B ) = 120 + 50 - ( 120 - 50 )

= 170 - 70

= 100.

But We need ,

n (A' n B') = n ( U ) - n ( A U B )

= 200 - 100

= 100.

Hence n (A' n B') = 100.