<p>Steve, the average speed is indeed 40 mph. But the problem could have asked what the DISTANCE was for either the round trip or one way. In the second case, one could use a numerator of … 1. It works this way with round trips of 1 hour. </p>
<p>As usual, 90 percent of the solution comes from reading the problem correctly and knowing how to solve it logically. </p>