A boat travels at a speed of 5 km/h in still water. It covers 30 km upstream and then returns downstream to the starting point in a total of 4 hours and 30 minutes. What is the speed of the current?
Explanation
The boat's speed in still water is 5 km/h. Given the total time for upstream and downstream travel is 4.5 hours for 30 km each way, the speed of the stream is calculated as 5 km/h.