1. The local train and the express train leave from the same station, and the local train is in the front, 48 kilometers per hour. After a period of time, the express train leaves from the same station, 72 kilometers per hour. After 2.5 hours, the express train catches up with the local train. How long did the local train take before the express train leaves? 2. Two water injection pipes inject water into the pool. A fills the pool for 5 hours and B fills the pool for 10 hours. How long does it take for two pipes to inject water at the same time to fill half of the pool? 3. To process a batch of parts, Party A and Party B shall work together for 4 days and Party A shall work alone for 6 days. Party A shall work for 2 days first and Party B shall work alone for the rest. How many days does it take for Party B to finish the rest? 4. To process a batch of parts, it takes 10 hours for Party A to do it alone, 8 hours for Party B to do it alone, and after 4 hours for Party A and Party B to do it together, the rest will be done by Party B alone. How long does it take for Party B to do the rest? 5. The teacher divided the candy for the children. If each person had 8, there would be 24 more. If each person had 10, there would be 2 less. How many students were there? 6. If someone makes 11 parts per hour within the specified time, he can finish them one hour ahead of time. If he makes 10 parts per hour, he can overfulfil 3 parts. How many parts are there in this batch? 7. Five carriages and four trucks can carry 24 tons of goods at a time, and ten carriages and two trucks can carry 21 tons of goods at a time? 8. Raising 8 horses and 15 cattle requires 162 kg of hay per day. It is known that feeding 5 horses needs 3 kg more hay per day than feeding 7 cattle. How many kg of hay does it need to feed a horse per day? What about cattle?

1. The local train and the express train leave from the same station, and the local train is in the front, 48 kilometers per hour. After a period of time, the express train leaves from the same station, 72 kilometers per hour. After 2.5 hours, the express train catches up with the local train. How long did the local train take before the express train leaves? 2. Two water injection pipes inject water into the pool. A fills the pool for 5 hours and B fills the pool for 10 hours. How long does it take for two pipes to inject water at the same time to fill half of the pool? 3. To process a batch of parts, Party A and Party B shall work together for 4 days and Party A shall work alone for 6 days. Party A shall work for 2 days first and Party B shall work alone for the rest. How many days does it take for Party B to finish the rest? 4. To process a batch of parts, it takes 10 hours for Party A to do it alone, 8 hours for Party B to do it alone, and after 4 hours for Party A and Party B to do it together, the rest will be done by Party B alone. How long does it take for Party B to do the rest? 5. The teacher divided the candy for the children. If each person had 8, there would be 24 more. If each person had 10, there would be 2 less. How many students were there? 6. If someone makes 11 parts per hour within the specified time, he can finish them one hour ahead of time. If he makes 10 parts per hour, he can overfulfil 3 parts. How many parts are there in this batch? 7. Five carriages and four trucks can carry 24 tons of goods at a time, and ten carriages and two trucks can carry 21 tons of goods at a time? 8. Raising 8 horses and 15 cattle requires 162 kg of hay per day. It is known that feeding 5 horses needs 3 kg more hay per day than feeding 7 cattle. How many kg of hay does it need to feed a horse per day? What about cattle?

The process omits 1:1.25
2：10/3
3：8
4：0.8
5：22
6：77
7：9/5、9/2
8：9、6