1, Xiaofeng walks from the terminal to the starting station along the bus route. When he started, a bus just arrived at the terminal. On the way, I met an oncoming bus on 14, and arrived at the starting station after 1 hour 18 minutes. At this time, another bus just left from the starting point. It is known that the distance from the departure station to the terminal station is 6000 meters, the speed of the bus is 500 meters/minute, and the departure interval between every two cars is certain. How many minutes is the departure interval of this train?
2. Xiao Zhang, Xiao Wang and Xiao Li set out from the same place by the lake at the same time and walked around the lake. Xiao Zhang's speed is 5.4 kilometers per hour and Xiao Wang's speed is 4.2 kilometers per hour. They both go in the same direction, while Xiao Li goes in the opposite direction. Half an hour later, Xiao Zhang met Xiao Li, and five minutes later, Xiao Li met Xiao Wang. So, how many kilometers is the journey around the lake?
3. Both Party A and Party B start to climb the mountain from the foot of the mountain at the same time, and go down immediately after reaching the top of the mountain. Their downhill speed is 1.5 times of their respective uphill speed, and Party A is faster than Party B. 1 hour later, A and B meet at the top of the mountain 600 meters. When B reached the top of the mountain, A just got down halfway up the mountain. So how many hours does it take for A to get back to the starting point?
4.a and B are the starting stations of trams. Every once in a while, a tram will be sent out at the same time. Xiao Zhang and Xiao Wang started from A and B by bike respectively, and went in opposite directions. Every tram meets an oncoming tram every 4 minutes; Xiao Zhang meets an oncoming tram every 5 minutes; Xiao Wang meets an oncoming tram every six minutes. It is known that the tram takes 56 minutes, so how many minutes did Xiao Zhang and Xiao Wang walk when they met on the way?
5. Two cars, A and B, leave from East Station and West Station at the same time. When we first met, car A traveled 80 kilometers, and the two cars continued to travel at the original speed, and each car returned immediately after arriving at the station. The second meeting place is 40 kilometers east of the first meeting place. How many kilometers are the East Station and the West Station apart?
2. Select the eighth grade Olympiad problem set.
1, the fast and slow cars started from the same place at the same time and caught up with the front cyclist along the same highway. It took the two cars 6 minutes and 10 minutes to catch up with the cyclist. It is known that the express train travels 400 meters per minute and the local train travels 320 meters per minute. How many meters do cyclists walk per minute?
2. The column of a special training battalion travels at a speed of 7 km/h, and the correspondent at the end of the team arrives at the head of the team at a speed of 1 1 km/h to deliver the letter, and then returns to the end of the team at the original speed, which takes 0.22 hours. Find the length of this team.
3. Party A and Party B are back to back, riding bicycles at the same time from the same place on the ring road. It is now known that it takes 70 minutes for A to walk once. If A and B meet 45 minutes after departure, how many minutes does it take for B to take a trip?
A cyclist trains between A and B, which are 950 kilometers apart. Start from a place and rest every 90 kilometers when you go; After arriving at the second place for a day's rest, return along the original road and rest every 100 km; He found that there happened to be a rest place that was the same as the rest place he went to. So how many kilometers is this rest place from A?
5. The circumference of a circle is 1.26 meters, and two ants start from both ends of a diameter at the same time and crawl along the circumference. These two ants climb 5.5 cm and 3.5 cm per second respectively. Every time they crawl 1 second, 3 seconds, 5 seconds ... (consecutive odd numbers), they turn and crawl. So, how many seconds did they crawl when they met?
3. Select the eighth grade Olympiad problem set.
1. The locksmith class in a workshop is divided into two teams to watch the tree planting work. There are twice as many people in the first team as in the second team. If 16 people are transferred from the first team to the second team, the remaining number of people in the first team is 3 people less than half of that in the second team. What is the original number of the first and second teams?
2. It is known that the profit of a store in March is 654.38+10,000 yuan, and the profit in May is1320,000 yuan, and the monthly growth rate in May is 10 percentage point higher than that in April.
3. The school arranges dormitories for boarding students. If there are seven people living in each dormitory, no six people can't arrange it. If there are 8 people living in each dormitory, then there are only 4 people living in one dormitory, and there are 5 empty dormitories. How many people are there?
4. One kilogram of peanuts can fry 0.56 kilograms of peanut oil, so how much peanut oil can be fried in 280 kilograms?
5. A batch of books are distributed to Class 1 10 and Class 2 15. How many books have been distributed in both classes now?
6. Both the master and the apprentice have to process the same number of parts. The master processes 50 parts per hour, more than the apprentice 10. During the work, the master stopped working for 5 hours, so the apprentice finished the task 1 hour earlier than the master. How many parts can each of them process?
7. A barrel of oil weighs 50kg. The first time the soybean oil was poured out, half of it was less than 4 kg, and the second time the remaining three quarters were two and two thirds kg more. At this time, the oil barrel weighs one-third of a kilogram. How much oil was there in the original barrel?
4. Select the eighth grade Olympiad problem set.
1.There is an expressway from city A to city B, which is divided into three sections. The first section, the speed is 40 km/h, the second section, the speed is 90 km/h, and the third section, the speed is 50 km/h. As we all know, the length of the first section of highway is exactly twice that of the third section. At present, two cars start from two cities, A and B, and move in opposite directions. 1 hour Twenty minutes later, they met in the second paragraph 1/3 (from A to B 1/3). Q: How many kilometers is it between A and B?
2. When two puppies just finished the length of railway bridge 1/3, a train came behind and a dog ran backwards. When they ran to the bridge B, the train just arrived at B; The other dog ran forward and reached the A bridge. The train just ran to A, and the speed of the two puppies was 6 meters per second. What is the speed of the train?
Xiaoming walked along the escalator from top to bottom. He walked 150 steps. His classmate Xiaogang walked down the escalator and took 75 steps. If Xiaoming walks at three times the speed of Xiaogang, what are the steps of the escalator that can be seen?
4, a car from A to B, if the speed is increased by 20%, it can arrive one hour earlier than the original time; If you drive at the original speed 120km and increase the original speed by 25%, you can arrive 40 minutes earlier. How many kilometers is the distance between Party A and Party B?
5. A dog chased a rabbit. Dogs have to jump six times, but rabbits can only jump five times. The distance that a dog jumps four times is the same as the distance that a rabbit jumps seven times. After the rabbit ran 5.5 kilometers, the dog began to chase. How far did the rabbit run and be caught up by the dog?
5. Select the eighth grade Olympiad problem set.
1. Two trains are running in opposite directions. Car A has a body length of 220m and a speed of10m per second. B the length of the car is 300 meters, and the speed is 16 meters per second. How many seconds does it take for two trains to pass by?
2. The length of the bus is182m, and it travels 36m per second. The length of the truck is148m, and it travels 30m per second. Two cars face each other on parallel tracks. How long does it take from meeting to taking the wrong bus?
There are two trains, one is140m long, the other is 230m long, and the other is13m per second. Now the two trains are going in opposite directions. How many seconds does it take for two trains to run into the train by mistake?
On the ascending and descending parallel tracks, two trains face each other. One train is182m long and runs at the speed of18m per second, while the other train runs at the speed of17m per second. It took 10 seconds for two trains to run into the train by mistake. How long is the other train?
5. The passenger train is 280 meters long and the freight train is 200 meters long. They walk opposite each other on parallel tracks, and it takes 20 seconds from the moment when two cars meet to the moment when the rear car leaves. If two cars are driving in the same direction, with the truck in front and the bus behind, the time from the moment when the front of the bus meets the rear of the truck to the moment when the rear of the bus leaves the front of the truck is 120 seconds. What are the speeds of the bus and the truck respectively?