Question

A boat can travel with a speed of 16 km/hr in still water. If the speed of the stream is 5 km/hr, find the time taken by the boat to go 63 km downstream.
1. 2 hours
2. 3 hours
3. 4 hours
4. 5 hours
5. None of these

Answer 1

Correct Answer - Option 2 : 3 hours

Given:

Speed of boat in still water = 16 km/hr

Speed of the stream = 5 km/hr

Boat to go 63 km downstream

Formula used:

Time = distance/speed

If the speed of a boat in still water is u km/hr and the speed of the stream is v km/hr, then,

Speed downstream = (u + v) km/hr

Calculation:

Speed downstream = (16 + 5) km/hr = 21 km/hr

Time taken to travel 63 km downstream = (63/21) hrs = 3 hrs

∴ Time taken to travel 63 km downstream is 3 hrs.