Question

Going against the current, a boat takes 6 hours to make a 120-mile trip. When the boat travels with the current on the return trip, it takes 5 hours.

What is the rate of the boat in still water?

Answer 1

22 miles per hour

Explanation:

Answer 2

22 miles per hour

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.