Question 4 [8 marks] Many families establish trusts for the children and relatives. There are two basic types of trusts: living trusts and testamentary trusts. Suppose a financial consultant has created 15 trusts for clients, and 8 are living trusts. A federal accountant is going to select 4 of the 15 trusts at random to be audited.

a. [1 mark] How many different ways are there to select 4 of the 15 trusts?

b. [2 marks] What is the probability that the federal accountant will select none of the living trusts? Leave answer to four decimal places.

c. [2 marks] What is the probability that the federal accountant will select at least one living trust?

d. [3 marks] What is the probability that the federal accountant will select at least three living trusts?