Henry Ernest Dudeney/Puzzles and Curious Problems/76 - How Far Was It

by : $76$

 * How Far Was It?
 * "The steamer," remarked one of our officers home from the East, "was able to go twenty miles an hour down-stream,
 * but could only do fifteen miles an hour upstream.
 * So, of course, she took five hours longer in coming up than in going down."


 * One could not resist working out mentally the distance from point to point.
 * What was it?