Two towns situated along a river are 120 km apart. A powerboat travels downstream for 5 hours and upstream for 12 hours. What is the speed of the river's current?

Correct answer marked below

5 km/h

6 km/h

7 km/h

Correct

8 km/h

9 km/h

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Explanation

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Official Explanation

Official

Let the speed of the boat be b and the speed of the river be r. For upstream travel:

b - r = 10

. For downstream travel:

b + r = 24

. By…

Comments

KartikayApr 9, 2024

thanks for posting

PatrickOct 8, 2024

thanks!

What this question tests

Your application of distance = rate × time to trains, boats, and commuters, including relative speed.

Mixing units (miles per hour vs. minutes) or averaging speeds — average speed is total distance over total time.