# The own speed of the ship is 27 km / h, the speed of the river is 3 km / h. How long will the motor ship spend on the way

**The own speed of the ship is 27 km / h, the speed of the river is 3 km / h. How long will the motor ship spend on the way between two piers, the distance between which is 120 km, if it will sail: a) along the river. b) upstream of the river?**

1. Let’s find the speed of the ship along the river, if the own speed of the ship and the speed of the river are known.

27 + 3 = 30 kilometers per hour.

2. Find out how much time the motor ship spent sailing 120 kilometers along the river.

120/30 = 4 hours.

3. Let’s calculate the speed of the ship against the river flow.

27 – 3 = 24 kilometers per hour.

4. Let’s calculate the time for which the motor ship passed 120 kilometers upstream of the river.

120/24 = 5 hours.

Answer: The motor ship sailed along the river for 4 hours, and against the river for 5 hours.