The distance between a and B is 360 km. A ship goes back and forth between a and B. It takes 18 hours downstream and 24 hours upstream. The static water velocity is x and the water velocity is y The distance between a and B is 360 km. A ship travels between a and B for 18 hours downstream and 24 hours upstream. Suppose that the speed of the ship in still water is x km / h and the water speed is y km / h, then the equations are formulated and explained carefully

The distance between a and B is 360 km. A ship goes back and forth between a and B. It takes 18 hours downstream and 24 hours upstream. The static water velocity is x and the water velocity is y The distance between a and B is 360 km. A ship travels between a and B for 18 hours downstream and 24 hours upstream. Suppose that the speed of the ship in still water is x km / h and the water speed is y km / h, then the equations are formulated and explained carefully

Still water speed + current speed = the speed of the ship sailing downstream
Still water speed - current speed = the speed of the ship sailing against the water
The distance between the two places is the same, both are 360 km
Speed * time = distance
therefore
(X+Y)*18=360
(x-y)*24=360
Solution
X=17.5
Y=2.5

A bicycle travels 12 kilometers per hour, and a motorcycle travels 1 kilometer per hour. It takes 3 minutes less than a bicycle. How many times is the speed of a motorcycle?

1 hour = 60 minutes, the speed of motorcycle: 1 △ 60 (60 △ 12-3) × 60, = 1 △ 2 × 60, = 30 (km / h); the speed of motorcycle is that of bicycle: 30 △ 12 = 2.5; answer: the speed of motorcycle is 2.5 times that of bicycle

A bicycle travels 12 kilometers per hour. A motorcycle travels 1 kilometer per hour, which takes three minutes less than a bicycle. The speed of a motorcycle is several times that of a bicycle
Detailed process

12 km = 12000 m 1 km = 1000 m 12000 / 60 = 200 (M / min) 1000 / 200 = 5 (min) 5-3 = 2 (min) 1000 / 2 = 500 (M / min) 500 / 200 = 2.5

The speed of a bicycle is 15 km / h, which is 1 / 3 of that of a motorcycle. How many km / h is the speed of a motorcycle?

15÷1/3=45