Each of 27 tourists was asked which of the countries Angola (A), Burundi (B) and Cameroon (C) they had visited. Of the group, 15 had visited Angola; 8 had visited Burundi; 12 had visited Cameroon; 2 had visited all three countries; and 21 had visited only one. Of those who had visited Angola, 4 had visited only one other country. Of those who had not visited Angola, 5 had visited Burundi only. All of the tourists had visited at least one of these countries.

A. Draw a fully labelled Venn diagram to illustrate this information.

b. Find the number of tourists in set B' and describe them.

c. Describe the tourists in set (A ∪ B) ∩ C' ‑ and state how many there are.

d. Find the probability that a randomly selected tourist from this group had visited at least two of these three countries.