Solve the problem.
-The speed of a stream is 4 mph. If a boat travels 64 mi downstream in the same time that it takes to travel 32 mi upstream, what is the speed of the boat in still water?
A) 15 mph
B) 14 mph
C) 12 mph
D) 8 mph

Question

Quizplus · Accepted Answer

The boat's speed in still water is 12 mph. Let the speed of the boat in still water be x mph. Downstream speed is (x + 4) mph and upstream speed is (x - 4) mph. The time taken for both journeys is the same, so 64/(x + 4) = 32/(x - 4). Solving this equation gives x = 12 mph.

Solve the Problem. -The Speed of a Stream Is 4 Mph. If a Mph