A motor boat travels 60 miles down a river in three hours but takes five hours to return upstream. Find the rate of the boat in still water and the rate of the current.

boat: 16 mph current: 4 mph

Step-by-step explanation:

speed = distance / time

The rate downriver is (60 mi) / (3 h) = 20 mi/h.

The rate upriver is (60 mi) / (5 h) = 12 mi/h.

The rate of the boat in still water is the average of these:

(20 + 12) / 2 mi/h = 16 mi/h

The rate of the current is the difference between the boat speed and actual speed:

16 mi/h - 12 mi/h = 4 mi/h