Question

if n (A)=15, (A union B) = 29, n (A intersection B) = 7 then n (B) = ?

Answer 1

n(a u b) =n(a)+n(b)-n(a intersection b)
29=15+n(b)-7
29=8+n(b)
n(b)=29-8
n(b)=21

Answer 2

Hey friend
here is your answer:-
GIVEN-n (A)=15
n (A union B)=29
n (A intersection B)=7
TO FIND-n (B)=?
n (A union B )=n (A)+n (B)-n (A intersectionB )
let n (B)=x
29=15+x-7
29=8+x
x=29-8
x=21
therefore n (B)=21
Hope it helps you
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