The boat sailed 60 km downstream for 3 hours against the current for 5 hours. Find the speed of the boat in still water.
1. Find out the speed of the boat as it moves along the river. To do this, divide the distance that the boat has sailed by the time taken to cover this distance:
60 km / 3 h = 20 km / h.
2. Find out the speed of the boat while it is moving against the stream of the river. To do this, we divide the distance that the boat sailed against the stream of the river by the time taken to overcome this distance:
60 km / 5 h = 12 km / h.
3. Let’s find out the difference in the speed of the boat upstream and downstream of the river:
20 km / h – 12 km / h = 8 km / h.
4. Find out the speed of the river:
8 km / h / 2 = 4 km / h.
5. Find out the speed of the boat in still water:
20 km / h – 4 km / h = 16 km / h.
Answer: the speed of the boat in still water is 16 km / h.