2. Rabbit A and Rabbit B compete in the 80-meter sprint, and both rabbits keep moving at a constant speed. When Rabbit A ran 40 meters, Rabbit B had already run 50 meters. How far is Rabbit A from the finish line when Rabbit B reaches it?
3. The ship sailed from A to B with smooth water at a speed of 25KM/h, and sailed from B to A with countercurrent at a speed of 15KM/h, and went back and forth for ***6 hours to find the distance between A and B. ..
Xiaohong read a story book, and read 1/7 five days ago. How many days does it take for the rest of us to read at the same speed?
5. The parts factory planned to produce 12000 parts in 30 days, but in fact, it produced 100 more parts every day than originally planned. How many days did it actually take to finish this task?
6. A project was originally planned to be completed in 35 people 18 days, and now it is required to be completed three days in advance. How many people will it take to complete it? Supplement to the question:
Can question 4.5.6 be solved with proportional knowledge?
The answer is 1.254.5kg Let the total mass of oranges be xkg, then the total mass sold in two days is: 40% x+140 = 0.4+140; The total mass of the remaining oranges is (1-40%) x-140 = 0.6x-140; So there is: (0.6x-140)/(0.4x+140) =1/3, and x=254.5kg is calculated.
2. 16m Let Rabbit A be x meters away from the finish line. Because the two rabbits advance at a constant speed, the distance they run in the same time is proportional: 40/50 = (80-x)/80; X= 16m, that is, the distance from rabbit A to the finish line is 16m.
3.56.25KM If the distance between Party A and Party B is X, the time for the ship to travel from Party A to Party B is X/25h, and the time for traveling from Party B to Party A is x/ 15h, the total time is X/25+X/15 = 6; Find x=56.25KM.
4.30 days because I read 1/7 in the first five days, so the remaining 6/7 needs: [5/( 1/7)]*(6/7)=30 days.
The design of 5.24 days actually took X days to complete. The original planned number of parts per day was 12000/30=400, but the actual number of parts per day was 400+ 100=500, so x*500= 12000 is x=24 days.
6.42. It takes X people to complete the current plan. According to the original plan, the total project quantity is 35 *18 = 630; Then according to the current scheme x*( 18-3)=630, x=42 people are obtained.