The primary air exchange system on a proposed spacecraft has four separate components (call them a, b, c, and d) that all must work properly for the system to operate well. Assume that the probability of any one component working is independent of the other components. It has been shown that the probabilities of each component working are p(a) = 0.95, p(b) = 0.90, p(c) = 0.99, and p(d) = 0.90. Find the probability that the entire system works properly.
a) 0.717
b) 0.941
c) 0.854
d) 0.891
