This puzzle is rated 3 star (hard).
bike travels downhill at 20 mph (miles per hour), on the level (flat road)
at 15 mph, and uphill at only 12 mph.
The bike takes 4 hours to travel from town A to town B. The return trip takes 4
hours and 40 minutes.
Find the distance between the two towns.
Check the solutions page for the correct answer.