2. The correspondent sent a letter from A to B, and immediately returned to A. * * * It took 3 hours and 52 minutes, with a speed of 30 km/h when he left and 28 km/h when he came back, to find the distance between A and B.
3.A walks 5 kilometers every hour, and after 2 hours, B rides a bike to chase A. ..
(1) If the speed of B is 20km/h, how long will it take for B to catch up with A?
(2) If B is required to go 14km to catch up with A, what is the speed of B?
1. Thinking about my mother going to the market to buy fruit. She first spent 3.5 yuan to buy 2.5 Jin of apples, and was going to buy 3 Jin of oranges. The unit price of oranges is 0.6 times that of 65438+ apples. How much should I pay for oranges?
Xiaohua borrowed a story book with 120 pages, and she read 36 pages in 3 days. If I can only borrow it for 8 days, how many pages do I have to read every day from the fourth day?
I bought 360 Jin of rice in the canteen and plan to eat 30 Jin every day. I actually ate three days more than planned. How many kilograms of rice do I actually eat every day?
4. Build a 340-kilometer expressway, with an average of 20 kilometers per day in the first two days. The rest are required to be repaired within 4 days. How many kilometers are repaired on average every day?
5. Two cars, A and B, leave from two places 396 kilometers apart at the same time. A car travels 85.8 kilometers per hour, and B car travels 90.2 kilometers per hour. A few hours later, two cars met.
6. A transport team wants to transport 84,000 bricks. If it transports 0.35 bricks per hour, it can transport them all on time. If you want to deliver all the goods four hours in advance, it will cost tens of thousands of dollars an hour.
7. A workshop can produce 65,438+020 type A parts, 65,438+000 type B parts or 200 type C parts every day. Three A-type parts, two B-type parts and 65,438+0 C-type parts can be made into a set. Now it is required to produce the most complete set of products within 30 days. How many days does it take to produce three parts, A, B and C?
8. A math book is 6.25 yuan and a Chinese book is 5.86 yuan. Two books and one * * *, how much is it?
9. A watermelon weighs 4.86 kg and a cantaloupe weighs 3.5 kg. How many kilograms is a watermelon heavier than a cantaloupe?
One-step multiplication and division of two decimal places 1 a kind of wool is 48.36 yuan per kilogram. How much is 3 kilos? Buy 0.6 kg?
2. A professional sericulture group raises 2 1 spring silkworm and one * * * produces1.24kg cocoon. How many kilograms of cocoons are produced per piece on average?
Three, three two-step calculation application problems with known conditions 1, Xiaohong read a story book for five days, reading 12 pages every day, but didn't read 38 pages. How many pages are there in this book? (Draw a line segment)
3 bags of flour and 3 bags of rice in the canteen. Flour is 25 kg per bag and rice is 50 kg per bag. How many kilograms of flour and rice are shipped?
3. The militia targeted the target, using 250 bullets for the first time, 320 bullets for the second time, and the third time was less than the sum of the previous two times 180 bullets. How many bullets were used for the third time?
Four, two-step calculation application problems under two known conditions
1. The school bought 45 boxes of colored chalk, and white chalk bought more than colored chalk 15 boxes. How many boxes of chalk do I buy?
2. An empty basket weighs 2kg, and there are 32kg peanuts in it. How many times the weight of the basket containing peanuts is that of the empty basket?
The Application of verb (Verb's abbreviation) Multiplication
1. The grain store sent two truckloads of flour, each with 80 bags of 25 kilograms. How many kilograms of flour did this grain shop send? (Answer in two ways)
2. Junior three students go to the vegetable garden to collect cabbages, which are divided into four groups, each group 1 1 person, with an average of 45kg per person. A * * * How many kilograms of cabbage?
1. The chemical fertilizer plant plans to produce 7,200 tons of chemical fertilizer, which has been produced for four months, with an average of 1200 tons of chemical fertilizer per month, leaving 800 tons per month. How many months will it take to complete the production?
2. The plastic factory planned to produce 1300 plastic modules, and produced 780 plastic modules in 6 days. According to this calculation, how many days will it take to produce the rest?
Li Shifu produced 252 parts in four hours in the morning, and worked at this speed for three hours in the afternoon. How many parts does Li Shifu produce on this day?
The cement plant plans to produce 3600 tons of cement, which will be completed in 20 days. In fact, it produces 20 tons more than planned every day. How many days does it actually take to complete the task?
5. A pile of 3.6 tons of coal is planned to burn 10 day. After improving the stove, it saves 0.06 tons per day compared with the original plan. How many days can this pile of coal burn now?
6. The distance between A and B is 420km, and a bus is planned to travel from A to B for 7 hours. In fact, its speed is more than planned 10 km. How many hours will it actually arrive?
7. Xiao Qiang goes back to school from home. If he walks 50 meters every minute, 12 minutes to go back to school. If he walks 10 meter per minute, he can go back to school a few minutes earlier.
8. Build a 6.4-kilometer expressway. In the first three months,1.2km was built on average every month, and the rest were repaired every month. How many months will it take?
9. Xiaoming spent 10.2 yuan on stationery, bought six pencils at 0.45 yuan each, and bought ballpoint pens for the rest. How many can he buy for each 2.5 yuan?
10. The garment factory originally planned to make 120 suits, each with 4.8m cloth. After improving the cutting method, each set saves 0.3 meters of cloth. How many sets of clothes can be made from the original cloth now?
1 1. A story book, originally 576 words per page, 25 pages. The second edition, with smaller words, only needs 18 pages. How many words are arranged on each page now than before?
12. A passenger train and a freight train leave from Party A and Party B at the same time. The speed of passenger trains is 80 kilometers per hour, and that of freight trains is 60 kilometers per hour. Five hours later, two trains met. How many kilometers is the railway between A and B?
13. Two engineering teams open1500m tunnel at the same time. Construction team A starts from one end and digs 14m every day. Construction team B starts from the other end and digs 16m every day. How many days can the tunnel be dug?
14. Party A and Party B type a 7000-word manuscript at the same time. Party A types 600 words per hour, and Party B types 200 words more than Party A. How many hours does it take to complete the task?
15. After school, Xiao Ming and Xiao Qiang walk in opposite directions at the school gate. Xiaoming walks 70 meters per minute, and Xiao Qiang walks 68 meters per minute. How many meters are they apart after 5 minutes?
16, the distance between a and b is 630 kilometers. Two hours after the bus departs from A, the truck departs from B. It is known that the speed of the bus is 65 kilometers per hour and the speed of the truck is 60 kilometers per hour. A few hours after the van left, it met the bus.
I wish you better and better grades. ~~! ! ~! ~ hehe
4. Party A and Party B practice race walking on the 400-meter circular runway. Party B walks 80 meters per minute, and Party A's speed is 1 and1/4 (1/4). Now Party A is in front of Party B 100 meters. How many minutes did they meet for the first time?
1. has a three-digit number, and its unit is three times smaller than the number on the 100th place, and the number on the unit is 1. If you exchange the number in the tenth place and the number in the hundredth place of this three-digit number to get a new number, then the original three-digit number is 270 times smaller than the new number and the original three-digit number is found.
2. The school has a four-story teaching building with six classrooms on each floor and three doors (two front doors and one side door of the same size) entering and leaving the building. The door was inspected during the safety inspection; When a main entrance and a side door are opened at the same time, 400 students can pass through in 2 minutes. If the main entrance has an average of 40 more students per minute than the side entrance.
(1) How many students can pass through a main entrance and a side door every minute on average?
(2) During the inspection, it was found that the efficiency of going out was reduced by 20% because students were too crowded in an emergency. According to the safety regulations, in case of emergency, students in the whole building should be evacuated safely through these three doors within 5 minutes. Suppose that each classroom in this teaching building has a maximum of 45 students. Q: Do these three doors meet the safety requirements? Why?
3. Party A and Party B walk from City A to City B. Party A walks 4 kilometers per hour, and Party B rides 8 kilometers per hour more than Party A. After half an hour, Party B sets out and both of them arrive at City B at the same time to find the distance between the two cities.
4. Several students in Education Middle School asked for cancellation. If there are 4 people living in each dormitory, there are 20 people left; If there are 8 people living in each dormitory, one dormitory is not empty and the others are full. Q: How many dormitories are there in this middle school? How many students are required to live on campus?
It costs 30 cents more to make a phone call for one minute than to send a short message. Now I know that the minutes of making a phone call for 8 yuan is equal to the number of text messages sent for 2 yuan. How much is the phone call per minute, and what is the cost of 1 message?
6. Xiao Qiang and Xiaohua practice running. Xiao Qiang runs 50 meters more than Xiaohua every minute, while Xiao Qiang runs 750 meters and Xiaohua runs 600 meters in the same time. What is their speed?
7. The distance between A and B is 80 kilometers. Three hours after a bus leaves from A, a car also leaves from A, which is three times as fast as the bus. It is known that the bus will arrive at B 20 minutes later than the bus. What is the speed of the two cars?
There is a 400-meter circular runway on the school playground. A and B start from the same place in reverse at the same time. The speed of A is x meters per second, and the speed of B is y meters per second. How long did it take them to meet for the third time?
9. It takes 12 days for project A and 12 days for project B.. C 15 days. Party A and Party C will work for 3 days first. Party A has something to leave and Party B will take part in the work. It will take several days to finish.