A friend says she has two new baby cats to show you, but she doesn't know whether they're both male, both female, or a pair. You tell her that you want only a male, and she telephones the vet and asks, "Is at least one a male?" The vet answers, "Yes!" What is the probability that if you select one kitten, then it is a male? Assume that a baby cat is equally likely to be female or male.