Over 1,000 people try to climb Mt. Everest every year. Of those who try to climb Everest, 31 percent succeed. The probability that a climber is at least 60 years old is 0.04. The probability that a climber is at least 60 years old and succeeds in climbing Everest is 0.005.

a. Find the probability of success, given that a climber is at least 60 years old.
b. Is success in climbing Everest independent of age?