Speed of a boat in standing water is 14 kmph and the speed of the stream is 1.2 kmph. A manrows to a place at a distance of 4864 km and comes back to the starting point. The total time taken by him is?
Answer: 700 hours
Explanation
Speed of the boat in standing water = 14 kmph
Speed of the stream = 1.2 kmph
Speed downstream = 14 + 1.2 = 15.2 kmph
Speed upstream = 14 - 1.2 = 12.8 kmph
Distance to the place = 4864 km (same for downstream and upstream)
Time taken downstream:
Time = Distance / Speed
= 4864 / 15.2
= 320 hours
Time taken upstream:
Time = Distance / Speed
= 4864 / 12.8
= 380 hours
Total time taken:
Total Time = Time downstream + Time upstream
= 320 + 380
= 700 hours
