Question 302482
 A cruise boat travels 48 miles downriver in 4 hours and returns to its starting point upriver in 12 hours. Find the speed of the river.
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48/4 = 12 mph downstream
48/12 = 4 mph upstream
The speed of the boat is the average (12+4)/2 = 8 mph
The current speed is the difference 12-8 = 4 mph