Answer 1

Let ’T’ be the set of people like Tea

Let ‘C’ be the set of people like Coffee

n(T ∩ C) = 45, n(T) = 35 and n(C) = 20

Let X be the number of people like both Tea and Coffee.

By using the Venn-diagram

From the Venn-diagram we get.

35 – x + x + 20 – x = 45

55 – x = 45

55 – 45 = x

10 = x

People do not like tea

= 20 – x

= 20 – 10

= 10