1. Passenger train conductor190m, freight train conductor 290m. The speed ratio of passenger cars to trucks is 5: 3. It is known that when they travel in the same direction, the crossing time of the two trains is 45 seconds. What is the speed of the bus per minute?

Solution: If the speed of the bus is X m/min, the speed on the truck is x*3/5 m/min.

x+3/5x=( 190+290)/(45/60)

Solution: x=400

The speed of the bus is 400 meters per minute.

A bus and a train are running in the same direction on parallel tracks. The bus is 200 meters long and the truck is 280 meters long. The speed ratio between the bus and the train is 5: 3, and the transit time for the bus to catch up with the train is 1 minute. Find out the speed of each car. If they travel in the same direction, how many minutes is their crossing time?

Suppose the speed of bus and train are 3x and 5x respectively.

Then (5x-3x)* 1=200+280.

2x=480

x=240

So the speed of bus and train is 3 * 240 = 720m/min, and 240 * 5 = 1200m/min.

Suppose that if driving in the opposite direction, the crossing time is t.

t*( 1200+720)=200+280

t=480/ 1920

=0.25 minutes