Question

If n (A) = 7, n (B) = 13, n (A $\cap$ B )= 4, then n (A $\cup$ B)=?

Answer 1

We have,

n (A) = 7, n (B) = 13 and n (A $\cap$ B) = 4

Since, n (A $\cup$ B) = n (A) + n (B) $-$ n (A $\cap$ B) = 7 + 13 $-$ 4

$\therefore$ n (A $\cup$ B) = 16