Probability

A probability problem:

Three students drive to school in the same car. They claim they were late to school and missed a test because of a flat tire. On the makeup test, the instructor asks the students to identify the tire that went flat: front driver’s side, front passenger’s side, rear driver’s side, or rear passenger’s side. If the students didn’t really have a flat tire and each randomly selects a tire, what is the probability that all three students select the same tire?