Verified answer

n(A) = 14 + 7 = 21

n(B) = 7 + 11 + 2 = 20

n(C) = 2 + 21 = 23

n(A ∪ B) = 14 + 7 + 11 + 2 = 34

n(B ∪ C) = 7 + 11 + 2 + 21 = 31

n(A ∪ C) = 14 + 7 + 2 + 21 = 44

n(A ∪ B ∪ C) = 14 + 7 + 11 + 2 + 21 = 55