The speed of a boat in standing water is 9 km/h and the speed of the stream is 1.5 km/h. a person rows to a place at a distance of 105 km and comes back to the starting point. The total time taken by him is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 24 hours.
Time = Distance/Speed
Downstream speed = Speed of boat in still water + Speed of stream
Upstream spedd = Speed of boat in still water - Speed of stream
According to the given question,
Total time taken = [105/(9 + 1.5)] + [105/(9 - 1.5)]
⇒ 105/10.5 + 105/7.5
⇒ 10 + 14 = 24 hours