Question

If n (A) =5 ,n (B) =7 and n(A^B) =3 find n (A^B)

Answer 1

n(AUB)= n(A) +n(B) -n(AnB)

Plug in the values

11 = 7 + 5 - n (AnB)

11 = 12 - n(AnB)

11–12 - -n (AnB)

-1 = - n(AnB)

So, n(AnB) = 1