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.