Solve.
-A cruise boat travels 48 miles downstream in 3 hours and returns to its starting point upstream in 12 hours. Find the speed of the stream.
A) 16 mph
B) 10 mph
C) 6 mph
D) 26 mph

Question

Quizplus · Accepted Answer

The speed of the stream is found by first determining the boat's speed in still water and the effect of the current on its speed. The downstream speed is 48 miles / 3 hours = 16 mph, and the upstream speed is 48 miles / 12 hours = 4 mph. The speed of the stream is the difference between the boat's speed in still water and its speed with the current, divided by 2. Thus, (16 mph - 4 mph) / 2 = 6 mph.

Solve. -A Cruise Boat Travels 48 Miles Downstream in 3 Hours