Three different people are to be selected at random, and each will be given one gift card. There is one card from Home Depot, one from Best Buy, and one from Red Lobster. The first person selected gets to choose one of the cards. The second person selected gets to choose between the two remaining cards. The third person selected gets the third card.

(a) If each card is equally likely to be selected, determine the number of sample points in the sample space. 

(b) Construct a tree diagram and determine the sample space. 

Determine the probability that

(c) The Best Buy card is selected first.

(d) The Home Depot card is selected first and the Red Lobster card is selected last.

(e) The cards are selected in this order: Best Buy, Red Lobster, Home Depot

Use the counting principle to determine the answer to part (a). Assume that each event is equally likely to occur.