Multiple choice

A person can row a distance of 16 km downstream in 2 hours and same distance upstream in 4 hours. What is the speed of boat in still water?

  1. 4 km/hr

  2. 6 km/hr

  3. 10 km/hr

  4. 12 km/hr

  5. 20 km/hr
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Downstream speed = 16/2 = 8 km/hr. Upstream speed = 16/4 = 4 km/hr. Speed in still water = (Downstream + Upstream) / 2 = (8 + 4) / 2 = 6 km/hr.

AI explanation

The downstream speed is the total distance divided by the time, which gives 16 divided by 2 to equal 8 km/hr. The upstream speed is 16 divided by 4 to equal 4 km/hr. Using the formula for the speed of a boat in still water, which is half the sum of the downstream and upstream speeds, we calculate (8 + 4) divided by 2. This equals 6 km/hr, so the correct answer is 6 km/hr.

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