For married couples living in a certain suburb, the probability that the husband will vote on a bond referendum is 0.21, the probability that the wife will vote on the referendum is 0.28, and the probability that both the husband and the wife will vote is 0.15. What is the probability that

(a) Only one member of a married couple will vote?

(b) a wife will not vote, given that her husband will not vote?

(c) a husband will vote, given that his wife will not vote?