Bob can row 14 mph in still water. The total time to travel downstream and return upstream to the starting point is 2.8 hours. If the total distance downstream and back is 36 miles, determine the speed of the river (current speed).

36/2=18
18/14+c +18/14-c=2.8
18(14-c)+18(14+c)=2.8(196-c²)
504=548.8-2.8c²
2.8c²=44.8
c²=16
c=±4
The current flows at 4 mph
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