A jet boat is used to take canoers 200 miles upriver to their starting point. As the driver of the jet boat, Jeremy knows that it will take him 5 hours to get the canoers upstream, but only 4 hours to get the boat back downstream after dropping the canoers off, as long as he keeps the boat moving at a constant speed.
How fast would the boat be moving in still water?
A.
5 mph
B.
40 mph
C.
45 mph
D.
50 mph