Multiple choice

The speed of a boat in still water is 5 km/hr and speed of current is 3 km/hr. If time taken tocover a certain distance upstream is 8 hours then how long will the boat take to cover the same distancedownstream?

  1. 2 hrs

  2. 3 hrs

  3. 2.5 hrs.

  4. 3.5 hrs.

  5. 1.5 hrs
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A Correct answer
Explanation

Upstream speed is 5 - 3 = 2 km/hr. Distance = 2 km/hr * 8 hrs = 16 km. Downstream speed is 5 + 3 = 8 km/hr. Time = 16 km / 8 km/hr = 2 hrs.

AI explanation

The upstream speed of the boat is the speed in still water minus the speed of the current, which is 5 km/hr minus 3 km/hr, equaling 2 km/hr. Using the formula distance equals speed multiplied by time, the distance covered upstream is 2 km/hr multiplied by 8 hrs, which equals 16 km. The downstream speed is the speed in still water plus the speed of the current, totaling 5 km/hr plus 3 km/hr, which equals 8 km/hr. The time to cover the same distance downstream is 16 km divided by 8 km/hr, resulting in 2 hrs.

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