Multiple choice

A boat takes 5 hours to travel 60 km downstream and 5 hours to travel 40 km upstream. What is the speed of the boat in still water?

  1. 8 km/hr

  2. 12 km/hr

  3. 10 km/hr

  4. 2 km/hr

  5. 20 km/hr
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C Correct answer
Explanation

Downstream speed = 60 km / 5 hr = 12 km/hr. Upstream speed = 40 km / 5 hr = 8 km/hr. Speed in still water = (12 + 8) / 2 = 10 km/hr.

AI explanation

Using the basic speed formula, the downstream speed is 60 divided by 5, which equals 12 km/hr, and the upstream speed is 40 divided by 5, which equals 8 km/hr. Applying the still water speed formula, (downstream speed + upstream speed) divided by 2, we get (12 + 8) divided by 2. This equals 20 divided by 2, resulting in a still water speed of 10 km/hr.

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