A boat has a speed of 14 kmph in standing water. The stream has a speed of 1.2 kmph. What time does the boat take to go to a distance of 4864 km and come back? (hours)
Answer: A
A boat travels at the speed of 14 km/hr in still water.
=> Speed of stream = 1.2 kmph
=> Speed of boat downstream becomes 14 + 1.2 = 15.2 kmph
=> Speed of boat upstream becomes 14 - 1.2 = 12.8 kmph
Total time taken in the journey = Journey downstream + Journey upstream
Therefore, 4864(1/12.8 + 1/15.2) = 700 hours