Tisch
1, and the weight ratio of apples in frames A and B is 4: 5. If you take 6 kg from B and put it in A, the weight ratio of the two frames is 5: 4. How many kilograms are there in two frames?
2. Magnifying the decimal part of a number by 3 times is 4. 1, and magnifying the decimal part by 9 times is 8.3. What is the number?
3. There is a copper-zinc alloy, and the weight ratio of copper to zinc is 2: 3. Now add 6 grams of zinc to get 36 grams of new alloy, and find the weight ratio of copper and zinc in the new alloy.
4. There is a round flower bed on the playground, and a pot of flowers is placed every 2dm around the flower bed, totaling 157 pots. What is the radius of this flower bed?
5. The middle of the track of the sports ground is a rectangle with a length of 100 m and a width of 40 m, and both ends are semicircular. In order to level the field, eight cars of yellow sand, each with 7 cubic meters, should be laid on the runway as evenly as possible. How do you think it should be distributed? (π takes 3. 14)
extreme
1. With the continuous growth of railway traffic, Chongqing North Railway Station is becoming more and more crowded. In order to meet the rapid development of railway traffic, the expansion project of the railway station began last year. In a project, the time for team A to complete alone is five months longer than that for team B, and the product of the time for two teams to complete alone is exactly six times the sum of the time for two teams to complete alone.
(1) How many months will it take for Team A and Team B to finish this project alone?
(2) If the monthly construction cost of Team A is 6,543,800 yuan, and the monthly construction cost of Team B is 500,000 yuan more than that of Team A, on the premise of ensuring the project quality, in order to shorten the construction period, it is planned to arrange Team A and Team B to work together to complete the project. In completing this project, the construction time of Team A is twice that of Team B. Then, how many months will it take Team A to make the project cost not exceed150,000 yuan? (The construction time of Team A and Team B shall be rounded off by the month)
2. A has money from 400 yuan and B has money from 150 yuan. If B gives some money to A, at this time, B's money is 10% of A's money. How much should B give A?
Our troops attacked the enemy at the bridge. When we set out, the enemy was 24 kilometers away from the bridge, and our army was 30 kilometers away from the bridge. The speed of our army's urgent March is 1.5 times that of the enemy. As a result, we arrived 48 minutes earlier than the enemy, so we asked our army to speed up.
It takes the same time for a ship to sail 80km downstream and 60km upstream. Given the current speed of 3 km/h, find the ship speed in still water.
5. When a middle school travels to a place 15km away from the school, the advance team and the brigade set out at the same time, with the speed of 1.2 times that of the brigade, and arrived at the destination half an hour in advance to make preparations. What's the speed of the advance team and the brigade?