In a photograph, Aristotle, David, Flora, Munirah, and Pedro are seated in a random order in a row of 5 chairs. If David is seated in the middle of the row, what is the probability that Pedro is seated beside him?
After David is seated, there are 4 seats in which Pedro can be seated, of which 2 are next to David. Thus, the probability that Pedro is next to David is 42 or 21.