Multiple choice

A man swims downstream 30 km and upstream 18 km taking 3 hours each time, what is the speed of the man in still water?

  1. 2 kmph

  2. 8 kmph

  3. 16 kmph

  4. 4 kmph
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Downstream speed = 30/3 = 10 kmph. Upstream speed = 18/3 = 6 kmph. Still water speed = (10 + 6) / 2 = 8 kmph.

AI explanation

The downstream speed is 30 km divided by 3 hours, equaling 10 kmph, while the upstream speed is 18 km divided by 3 hours, equaling 6 kmph. Using the formula for boat speed, which is (Downstream Speed plus Upstream Speed) divided by 2, we add 10 and 6 to get 16, and then divide by 2. The speed of the man in still water is 8 kmph.

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