32. From a small town 120 persons were selected at random and asked the following question:

Which of the three shampoos, A, B, or C, do you use? The following results were obtained: 20 use A and C, 10 use A and B but not C, 15 use all three, 30 use only C, 35 use B but not C, 25 use B and C, and 10 use none of the three. If a person is selected at random from this group, what is the probability that he or she uses

(a) only A;

(b) only B;

(c) A and B? (Draw a Venn diagram.)