Question: If a boat goes 30 km upstream in 3 hours, what is the speed of the current if the speed of the boat in still water is 12 km/h?
Options:
Correct Answer: 4 km/h
Solution:
Speed upstream = Distance/Time = 30 km / 3 h = 10 km/h. Speed of current = Speed in still water - Speed upstream = 12 km/h - 10 km/h = 2 km/h.