Answer:
22 miles per hour
Step-by-step explanation:
Against the current, the boat's rate of travel is ...
(120 mi)/(6 h) = 20 mi/h
With the current, the boat's rate of travel is ...
(120 mi)/(5 h) = 24 mi/h
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The sum of boat speed (b) and current speed (c) is 24 mph. The difference is 20 mph. This lets us write the equations ...
b + c = 24
b - c = 20
Adding these two equations together, we get ...
2b + 0c = 44
b = 22 . . . . . . . . divide by 2
The rate of the boat in still water is 22 miles per hour.
