The distance between the two berths is 54 km. How much time will the boat spend
The distance between the two berths is 54 km. How much time will the boat spend on the way from one berth to another and back, if its own speed is 22.5 km / h, and the speed of the river is 4.5 km / h?
1) Find the speed of the boat while moving along the river. It is necessary to add the speed of the river to the boat’s own speed.
22.5 + 4.5 = 27 (km / h)
2) Find the speed of the boat when moving against the stream of the river. It is necessary to subtract the speed of the river from the boat’s own speed.
22.5 – 4.5 = 18 (km / h)
3) Find the travel time when the boat moves along the river. To find the time, you need to divide the distance by the speed.
54: 27 = 2 (h)
4) Find the travel time when the boat moves against the river.
54: 18 = 3 (h)
5) Let’s find how much time the boat will spend moving from one berth to another and back.
2 + 3 = 5 (h).
Answer. 5:00.