@elizabeth, how long’s the hill? See the question its given he completed half distance in at an average speed of only three miles per hour....it means exactly the half distance....If its provided the distance..then you can solve it in a bit... are both sides of the hill the same length? See he is talking about return trip downhill not to the other side Answer: What i think is..it's impossible... You can't average speed and distance. put an arbitrary distance to it and you realize you have used up all your time in the first half.

how long's the hill? are both sides of the hill the same length?