Let Set A of people who like apples and Set B of people who like orange and U is set of all people Given n(A) = 24, n(B) = 18 and n(U) = 50 Also given n(A ∩ B) = 5 n(A ∪ B) = n(A) + n(B) - n(A ∩ B) ⇒ n(A ∪ B) = 24 +18 - 5 ⇒ n(A ∪ B) = 37 Now, if Set C is of people who likes only grapes n(C) = n(U) - n(A ∪ B) n(C) = 50 + 37 = 13 ∴ People who likes only grapes n(C) = 1