1 A and b are 7: 3. If their prices rise after 700 yuan, the price ratio is 7: 4. What are the original prices of these two commodities?
Solution: Let B be the original price X.
(7x/3+700):(x+700)= 7:47x+4900 = 28x/3+28007 x/3 = 2 100 x = 9007 x/3 = 7 * 900/3 = 2 100。
2. The ratio of goods in warehouse A and warehouse B is 6: 5. Later, warehouse A received 180 tons and warehouse B received 30 tons. At this time, the cargo ratio of warehouse A and warehouse B is 18: 1 1. How many tons were there in the original two warehouses?
Solution: let the original price of b be X.
(6x/5+180): (x+300) =18:18x+5400 = 66x/5+1980 24x/5 = 3420.
Xiaoming walked 6 kilometers per hour from A to B, 9 kilometers per hour when he came back, and it took him 5 hours to go back and forth. How many kilometers did Xiaoming walk back and forth?
Time remaining: Return time = 1/6: 1/9=3:2 Time remaining =5÷(3+2)×3 = 1×3 =3 (hours) Distance = 6× 3 =1.
4. It takes 4 hours for a car to travel between Station A and bilibili. It is known that the speed of the car is 45 kilometers per hour when it goes and 30 kilometers per hour when it comes back. How many kilometers is the distance between Station A and bilibili?
Remaining time: Return time = 1/45: 1/30=2:3 Remaining time =4÷(3+2)×2 =4/5×2 =8/5 (hours) Distance =45×8/5=72 (.
5. Class A, B, C and D are green trees, with class A accounting for 3/20 of the total, class B accounting for 25% of the total, and the ratio of class C to class D is 5: 6. If A is less 12 trees than Class B, how many trees will Class D plant?
Total number =12/(25%-3/20) =120 (trees) c and d * * * =120× (1-25%-3/20) =/kloc-.