12) 3.3.7(185) There are 11items of

12) 3.3.7(185) There are 11items of a product on a shelf in a retail outlet, and unknown to the customers, four of the items are outdated. Suppose that a customer takes three items at random.
(a) What is the probability that none of the outdated products are selected by the customer?
(b) What is the probability that exactly two of the items taken by the customer are outdated?