A campus student club distributed material about membership to new students attending an orientation meeting. Of those receiving this material $40 \%$ were men and $60 \%$ were women. Subsequently, it was found that $7 \%$ of the men and $9 \%$ of the women who received this material joined the club.
a. Find the probability that a randomly chosen new student who receives the membership material will join the club.
b. Find the probability that a randomly chosen new student who joins the club after receiving the membership material is a woman.