Let people have brown hair = A and people have brown eyes = B Then, n(A) = 40%, n(B) = 30%, n(A ∩ B) = 12% ∴ n(A ∪ B) = n(A) + n(B) – n(A ∩ B) = 40 + 30 – 12 = 70 – 12 = 58% ∴ The number of people in town have neither brown hair nor brown eyes = 100 – n(A ∪ B) = 100 – 58 = 42%.