Originally Posted by schoy
Probability that Bob takes one of the ends: 2 out of 5 seats (2/5)
Probability that Lisa takes the other end: 1 out of the remaining 4 seats (1/4)
2/5 x 1/4 = 2/20 = 1/10
Edit: BTW, as you can tell by the calculation, OP is misreading the question. In order to sit next to only one other person, Bob and Lisa must necessarily sit at the ends.
schoy, you are correct.
Bob and Lisa are both students, so both count in terms of 'sitting next to one student'.