Question 1077584
Two bicyclists start twenty miles apart and head toward each other, each going at a steady rate of 10 mph.
 At the same time, a fly that travels at a steady 15 mph starts from the front wheel of the southbound bicycle and flies to the front wheel of the northbound bicycle, then turns around and flies to the front wheel of the southbound one again, and continues in this manner until he is crushed between the two front wheels.
 Question: What distance did the fly cover?
:
The relative speed between the bicycles going toward each other is 20 mph
Therefore it would take 1 hr for them to travel a total of 20 mi and collide
:
During the this hour the fly is going 15 mph, therefore:
15 * 1 = 15 mi is the distance traveled by the fly