1. The distance between the two stations is 275 kilometers. The local train goes from Station A to bilibili at a speed of 50 kilometers per hour. 1h later, the express train runs from bilibili to Station A at a speed of 75km/ h. How many hours after the local train leaves, will you meet the express train? Suppose that an hour after the local train leaves, it meets the express train 50a+75 (a-1) = 2750a+75a-75 = 275125a = 350a = 2.8 hours. 2. A car travels from place A to place B at a speed of 40 kilometers per hour. Three hours later, due to the rain, the average speed was forced to decrease by 65430 per hour. Suppose the original time is 1 hour 45 minutes =3/4 hours. According to the question, 40a = 40× 3+(40-10 )× (a-3+3/4) 40a =120+30a-67.510a = 52.5a = 5.25. 4=2 10 km 3. The locksmith class in a workshop is divided into two groups. Look at the tree planting work. The number of people in Team A is twice that of Team B. If 16 people are transferred from Team A to Team B, the number of people left in Team A will be less than half that of Team B. What about the original numbers of Team A and Team B? Solution: Assuming that Team B originally had A and Team A had 2a, then according to the meaning of the problem, 2A-16 =1/2× (A+16)-34a-32 = A+16-63a = 42a =/kloc. Team A used to have 14×2=28 people, but now team B 14+ 16=30 people, and team A has 28- 16= 12 people. 4. It is known that the profit of a store in March is 65,438+10,000 yuan, and the profit in May is 12 yuan. Solution: Let April's profit be X, then X * (1+10%) =13.2 So x= 12 Let March's growth rate be Y, then10 * (1+) How many people are there? Solution: In Room A, the total number of people is 7a+6 = 8 (A-5-1)+47a+6 = 8a-44a = 50 =7×50+6=356. One kilogram of peanuts can fry 0.56 kilograms of peanut oil, so how much peanut oil can be fried in 280 kilograms? According to the proportion, we can fry one kilogram of peanut oil1:0.56 = 280: AA = 280× 0.56 =156.8kg. The complete formula is: 280 ÷1× 0.56 =156.8kg. Solution: Assuming that the total number of books is A =a/ 10 and the number of students in Class 2 is a/ 15, it will be distributed to Class 2 on average, with each student being A/(A/10+A/15) =10×. How many people are there in this team? A * *, how many seedlings? Solution: There is a person 5a+14 = 7a-62a = 20a = 10 * * There is10, and there is a person with a sapling of 5× 10+ 14=64 trees. A barrel of oil with 50kg, pouring out soybean oil for the first time. Solution: If the oil weighs one kilogram, the barrel weighs 50-a kilograms, and the first time it is poured out 1/2a-4 kilograms, the remaining 1/2a+4 kilograms is poured out 3/4× (1/2a+4)+8/3 = 3/8a+for the second time. There is1/2a+4-3/8a-17/3 =1/8a-5/3kg of oil left. According to the question,1/8a-5/3+50-a =1/348 = 7. (1 class 42, class 2 43, class 3 45) Personal A is 96 meters. According to the meaning of the question, 96: a = 33:1533a = 96×15a ≈ 43.6, which is suitable for class 2, but there is not much left, which is not enough for class 3. If the numerator adds 73 and the denominator adds 37, then the new score is reduced to 1/2, and the original score is found. Solution: let the original fractional molecule add 123, The denominator minus 163 is 3a/4a (3a-123+73)/(4a+163+37) =1/26a-100 = 4a+202a. How many kilograms is this batch of fruit (equation solved)? Let's assume that the fruit originally has a kilogram of 60+60/(2/3) =1/4a60+90 =1/4a =150a = 600kg of fruit originally has 600kg of 65438. (Solve by equation) Suppose there is a ton of a× (1-3/5)+20 =1/2a0.4a+20 = 0.5a0.1a = 20a = 200, and there are 200 tons 14, Uncle Wang. What is the area of this vegetable field? Solution: Let the length and width be 5m respectively. 2a m According to the meaning of the question, 5a+2a×2=48 (the wall is the width at this time), 9a=48 a= 16/3, length =80/3 m, width =32/3 m, area = 80/3x16/3 =1280/. The second type: no monthly fee, call charge per minute, 0.4 yuan. If you talk for 80 minutes a month, which billing method is cheaper? If you talk for 300 minutes a month, which billing method is cheaper? Suppose you talk for one minute every month. When the two charges are the same, 22+0.2a = 22a = 1 10. So when you talk with the same charge for 80 minutes, use the second 22+0. When 0.4×80=32 passes 300 minutes, use the first 22+0.2× 300 = 82.