Question

A motorboat travels 448 kilometers in 8 hours going upstream and 440 kilometers in 5 hours going downstream. What is the rate of the boat in still water and what is the rate of the current?

Answer 1

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Answer:

• boat: 72 km/h
• current: 16 km/h

Explanation:

The speed difference between boat and current is the upstream rate:

(448 km)/(8 h) = 56 km/h

The sum of speeds of boat and current is the downstream rate:

(440 km)/(5 h) = 88 km/h

The rate of the boat is half the sum of these:

(56 +88)/2 = 72 . . . km/h

The rate of the current is half their difference:

(88 -56)/2 = 16 . . . km/h

The rate of the boat is 72 km/h; the rate of the current is 16 km/h.