2020 Classic Junior High School Grade Two Olympiad Math Puzzle (1)
1. Xiao Wang and Xiao Li live on the first floor. They work from home. Xiao Wang walked for 20 minutes before Xiao Li left. Given that Xiao Li's speed is three times that of Xiao Wang, how long will it take Xiao Li to catch up with Xiao Wang after starting?
2. A walks 80 meters per minute and B walks 50 meters per minute. In the afternoon 1: 30, they walked back in the same place for 6 minutes. A turned around and caught up with B. When did A catch up with B?
A school organized students to go to the Great Wall for a spring outing and rented a bus. The distance from the school to the Great Wall is150km. The bus and a school bus leave from school at the same time. When the bus arrived at the Great Wall, the bus was still 30 kilometers away. Given a bus speed of 60 kilometers per hour, how many kilometers is the bus faster than the bus?
4. Party A and Party B start from two opposite vertices of a square pool with a circumference of 800 meters and walk counterclockwise at the same time, with Party B in the front and Party A in the back. A walks 50 meters per minute, and B walks 46 meters per minute. How long does it take for A and B to leave at the same point?
5. Party A and Party B set out from East Village to West Village at the same time. Party A's speed is 6 kilometers per hour, while Party B's speed is 4 kilometers per hour. Party A rested for 2 hours, and the result was later than Party B 1 hour. What is the distance between the two villages?
2020 Classic Junior High School Grade Two Olympiad Math Puzzle (2)
1. For a project, it takes 15 days for Team A to do it alone, and 20 days for Team B to do it alone. How many days does it take for two teams to work together?
2. It takes 6 hours for Party A to do a job alone, 4 hours for Party B and 3 hours for Party C.. How many hours does it take three people to work together?
3. A pool is equipped with three water pipes, A, B and C. A and B are water inlet pipes and C is water outlet pipe. By opening the first tube, the empty pool can be filled in 2 hours, the second tube can be filled in 3 hours and the third tube can be filled in 4 hours. Three pipes are open at the same time. How long will it take to fill the empty pool?
4. A project can be completed by Party A in 8 days, while Party B can only complete 4/5 of the project in 8 days. If Party A cooperates with Party B, how long will it take to complete the project?
5. Party A will complete a batch of parts within 12 days, and Party B will complete it within 8 days ... Party A and Party B will cooperate for 3 days first, and Party B will complete the rest alone. How many days will it take?
2020 Classic Junior High School Grade Two Olympiad Math Puzzle (3)
1, Party A and Party B walk in opposite directions from two places 90km apart at the same time. A travels 8 kilometers per hour, and B travels 2 kilometers more than A. They met on the road a few hours later.
Party A and Party B set out from two places 99 kilometers apart and meet three hours later. It is known that Party A travels15km per hour. How many kilometers does Party B travel per hour?
3. Both parties ride in opposite directions from two places at the same time. Party A's speed is 20km per hour, and Party B's speed is18km. They met at a distance of 3 kilometers from the midpoint. How many kilometers are there between these two places?
The two trains leave from two cities, A and B, at the same time. Train A travels 76 kilometers per hour and train B travels 82 kilometers per hour. Three hours after the departure, the distance between the two trains is still 156 km. How many kilometers are the two cities apart?
5. The distance between Party A and Party B is 384 kilometers, and the two cars start from two places relatively. Car A travels 38 kilometers per hour and car B travels 42 kilometers per hour. Car A left 64 kilometers before the two cars started. A few hours before the two cars met.
2020 Classic Junior High School Grade Two Olympiad Math Puzzle (4)
1. The volume of the pool is 100 cubic meter, with two water inlet pipes and one drainage pipe. It takes 10 hour and 15 hour for the two pipelines to fill the tank respectively. There is some water in the pool. If two pipes are filled with water at the same time and the drain pipe is drained, it will take 6 hours to drain the water in the pool. If a pipe is flooded and the drain pipe is drained, it will take 2 hours to drain the water in the pool. How many cubic meters of water was there in the pool?
2. A pool with a normally open drain at the bottom and several water inlet pipes with the same thickness at the top. Four water inlet pipes are opened, and it takes 5 hours to fill the pool. Two water inlet pipes are opened, and it takes 15 hours to fill the pool. Now the pool needs to be filled in 2 hours, so how many water inlet pipes should be opened at least?
3./kloc-You can finish a project independently in 0/2 days. Party A will do it for 3 days, and the rest will be done by Party B, and Party B will do it for 6 days. How many days does it take for Party A to do it for 6 days?
Two teams dug a canal in 30 days. It's been 12 days now, and the rest was dug by team B, and it took 24 days to finish. How many days does it take for Team B to dig this canal?
5. Passenger cars and trucks leave from Station A and bilibili relatively simultaneously. After 2 hours and 24 minutes, the bus traveled 9.6 kilometers more than when the truck met. It is known that the bus travels from Station A to bilibili for 4 hours and 30 minutes. What are the speeds of buses and trucks?
2020 Classic Junior High School Grade Two Olympiad Math Puzzle (5)
1 and two trains, A and B, leave from A and B at the same time and run in opposite directions. The speed of train A is 75 kilometers per hour, and that of train B is 69 kilometers per hour. 18 hours later, two trains met on the way. How long is the railway between these two places?
2. Two cars, A and B, which are 480 kilometers apart, set off at the same time and walk in opposite directions. It is known that it takes 6 hours for a car to travel from city A to city B, and it takes 12 hours for a car to travel from city B to city A.. How many hours after the two cars left?
The two trains A and B leave from two places 700 kilometers apart at the same time. Car A travels 75 kilometers per hour. Five hours after the meeting, how many kilometers per hour will the B train run?
4. The students of Team A and Team B started from two places 18km apart and walked in opposite directions at the same time. A classmate keeps cycling back and forth between the two teams at the speed of 14 km per hour. Team A travels 5 kilometers per hour, while Team B travels 4 kilometers per hour. How many kilometers did the cyclists walk when the two teams met?
The distance between east and west towns is 20 kilometers. Party A and Party B set out from two towns at the same time, going in opposite directions. The distance traveled by Party A per hour is twice that of Party B, and after 3 hours, the distance between them is 56 kilometers. What is their speed?