Question

If a and b are two sets such that n(a) =115, n (b) = 326, n (a-b) =47 , then write n(abab).

Answer 1

$\huge{\boxed{\mathtt{\red{ANSWER}}}}$

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

As given

n(A) = 115 , n(B) = 326 , n(A-B) = 47

Put in the above property.

47 = n (A U B) - 326

n (A U B) = 326 + 47

n (A U B) = 373 (Ans)