Question

If n(A) =15 n(AuB) =31,n(AnB)=9 then n(B)=?​

Answer 1

Answer:

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Step-by-step explanation:

Given:

n(a)=15

n(a\cup ba∪b )=29

n(a\cap ba∩b )=7

To find:

n(b)

Solution:

We know that

n(a\cup ba∪b )=n(a)+n(b)-n(n\cap bn∩b )

To find the value of b we are using the above formula

Now, substitute the values then, we get

29=15+n(b)-729=15+n(b)−7

n(b)=29-15+7n(b)=29−15+7

n(b)=21n(b)=21

Hence, the value of n(b)=21

Answer 2

Answer:

then n(b)= n(AuB) - n(A) = 31-15 = 16.