Question

a cruise boat tavels 72 miles downstream in 3 hours and returns to it starting point upstream in 12 hours Find the speed of the stream.

Answer 1

Explanation:

72 mi / 3hr = 21 mi/hr

72 mi / 12 hr = 6 mi / hr

21 - x = 6 + x

15 = 2x

x = 7.5 mi/hr current speed