The fast and slow trains leave from a and B at the same time and meet each other after 5 hours. After meeting, the two trains continue to drive at the original speed and arrive at B after 3 hours. The slow train is 180 km away from A. how long is the highway between a and B?

The whole journey of express train takes 5 + 3 = 8 (hours). After the two trains meet, the distance of express train takes up 3 △ 8 = 38 of the whole journey, the distance of slow train takes up 38 △ 5 = 340 of the whole journey, and the distance of slow train takes up 340 × 8 = 35 of the whole journey. The highway length of a and B is 180 △ 1-35, = 180 △ 25, = 450 (km). Answer: the highway length of a and B is 450 km

A freight car departs from a place to B at 6 am, traveling 45 kilometers per hour on average. A passenger car departs from B place to a place, 15 kilometers faster than the freight car on average. It is known that the passenger car departs 2 hours later than the freight car. At 12 noon, the two cars pass a station on the way at the same time, and then continue to move forward. When the passenger car arrives at a place, how many kilometers is the freight car from B place?

① Bus speed: 45 + 15 = 60 (km); ② distance between two places: 45 × (12-6) + 60 × (12-6-2), = 45 × 6 + 60 × 4, = 510 (km); ③ time required for bus to complete the whole journey: 510 ／ 60 = 8.5 (H); ④ distance between bus and B when bus arrives at a place: 510-45 × (8.5 + 2), = 510-472.5, = 37.5 (km); A: when the bus arrives at land a, the truck is 37.5 kilometers away from land B

The distance between a and B is 575km. A bus runs 55km per hour from a place. One hour later, a truck runs 75KM per hour from B place?
To solve a series of equations or equations

(575-55) / (55 + 75) = 520 / 130 = 4 hours
55x (1 + 4) = 55x5 = 275 km

As shown in the figure, the & nbsp; 35 of the small square is covered by the shadow, and the & nbsp; 56 of the large square is covered by the shadow. Then, what is the ratio of the shadow area of the small square to the shadow area of the large square______ ．

Small square area × (1-35) = large square area × (1-56), that is, small square area × 25 = large square area × 16, so small square area: large square area = 16:25 = 5:12, then small square area is 5 parts, large square area is 12 parts, so small square covered by shadow is 5 × 35 = 3 parts, large square covered by shadow is 12 × 56 = 10 parts The area ratio of the shadow part of the small square to that of the large square is 3:10

The fast and slow trains leave from a and B at the same time and meet each other after 5 hours. After meeting, the two trains continue to drive at the original speed and arrive at B after 3 hours. The slow train is 180 km away from A. how long is the highway between a and B?