A study of radio listening behavior of married men and women during prime-time listening hours. Based on past listening records, it has been determined that during prime time, husbands are listening to the radio 60% of the time. When the husband is listening to the radio, 40% of the time the wife is also listening. When the husband is not listening to the radio, 30% of the time the wife is listening to the radio. Find the probability that:

a. If the wife is listening to the radio, the husband is also listening to the radio.
b. The wife is listening to the radio during prime time.