Spanish study group is pairing off to prepare for the exam. The study group has seven members, so there will be three pairs and one member who must study alone. Names are drawn from a hat so all combinations are equally likely. (a) What is the probability Pierce will have to study alone? (b) What is the probability that Troy and Abed will not be paired together? (c) What is the probability Jeff will be paired with either Annie or Britta?