1. Passengers and trucks leave from A and B relatively simultaneously. This bus travels 75 kilometers per minute. Four hours later, the bus passed the midpoint of 20 kilometers. At this time, the bus and truck are still 24 kilometers apart. How many kilometers does this truck travel per hour?

If the truck travels x kilometers per hour, it must:

24/(75-x)==4

75-x==6

x==59

So the truck travels 59 kilometers per hour.

2. The two cars started from the South and North Stations at the same time, met for the first time at a distance of 55 kilometers from the South Station, and then the two cars continued to drive at the original speed. They returned immediately after arriving at each other's departure place and met again at 15km south of the midpoint. How many kilometers are the two stops apart?

Solution,

(55×3+ 15)÷( 1+ 1/2)

= 180÷ 1.5

=120km

3. Cars and buses set out from cities A and B at the same time, returned immediately after reaching their respective starting points, and met for the second time on the way, with a distance of180km. It is known that cars travel 100 kilometers per hour and buses travel 80 kilometers per hour. What's the distance between a and b?

Solution, get:

The speed ratio is 100: 80 = 5: 4.

5/(4+5) = 5/9 of the whole journey of the first car.

The distance between the second meeting car and the starting point is 2-5/9x3 = 1/3.

The distance between A and B is180 ÷ (5/9-1/3) =180 ÷ 2/9 = 810km.

Xiaoming's home is 2300 meters away from school. My younger brother started from home and my younger brother started from school five minutes later. The two men walked in opposite directions. 10 minutes later, my brother met my brother. If my brother walks 20 meters more than his brother every minute, how many meters do they walk every minute?

Solution, get:

Let my brother walk x meters per minute and my brother walk x+20 meters per minute.

5×(X+20)+ 10×(X+20+X)= 2300

5X+ 100+20X+200=2300

25X=2300-300

X=2000÷25

X=80

My brother walks 80 meters per minute, and my brother walks 80+20 = 100 meters per minute.

5. Two trucks, one big and one small, transport fertilizer from the factory to Wangcun at the same time. The speed of big trucks is 50 kilometers per hour, and that of small trucks is 40 kilometers per hour. The big truck stopped for 2 hours on the way to repair the car, so it arrived at Wangcun 0.5 hour later than the small truck. How many kilometers is the distance from Qiuchang to Wangcun?

Solution, get:

(2-0.5)÷( 1/40- 1/50)

= 1.5÷ 1/200

=300 km

6. Party A, Party B and Party C walk 60 meters per minute, Party B walks 80 meters per minute and Party C walks 70 meters per minute. Now A and B start from school, and C meets A two minutes later. How many meters is the school from the book city?