7. Consider rolling a fair 6-faced die twice. Let A be the event that the sum of the two rolls is equal to 7, and B be the event that the first one is an odd number

. (a) What is the probability that the sum of the two rolls is equal to 7 given that the first one is an odd number? Show all work. Just the answer, without supporting work, will receive no credit.

(b) Are event A and event B independent? Explain.