Multiple choice

Daniel is running his boat downstream and covers a distance of 32 km in 4 hours. What will be the speed of the boat in still water, if he covers the same distance upstream and takes 8 hours to complete?

  1. 7 kmph

  2. 6 kmph

  3. 5 kmph

  4. 4 kmph

  5. 3 kmph
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Downstream speed = 32/4 = 8 kmph. Upstream speed = 32/8 = 4 kmph. Boat speed = (8 + 4) / 2 = 6 kmph.

AI explanation

Using the basic Time, Speed and Distance formula, the downstream speed is 32 km divided by 4 hours, which equals 8 kmph. The upstream speed is 32 km divided by 8 hours, which equals 4 kmph. Using the boat and stream formula for speed in still water, calculate the average of these two speeds: (8 + 4) divided by 2. This gives the boat's speed in still water as 6 kmph.

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