Li Wei rides a motorcycle from home to the railway station. If he travels 30 kilometers per hour, he will be 15 minutes earlier than the train. If he travels 18 kilometers per hour, he will be 15 minutes later than the train's departure time. If Li Wei plans to arrive at the railway station 10 minutes before the train leaves, what's the speed of his motorcycle at this time?

Li Wei rides a motorcycle from home to the railway station. If he travels 30 kilometers per hour, he will be 15 minutes earlier than the train. If he travels 18 kilometers per hour, he will be 15 minutes later than the train's departure time. If Li Wei plans to arrive at the railway station 10 minutes before the train leaves, what's the speed of his motorcycle at this time?

Let the departure time of the train be x hours. From the meaning of the question: 30 (x-1560) = 18 (x + 1560), the solution is x = 1. Let Li Wei's cycling speed be y kilometers per hour, y = 30 × (1 − 1560) 1 − 1060 = 27. Therefore, Li Wei's cycling speed is 27 kilometers per hour

If you go to the railway station by motorcycle from home, if you walk 30 kilometers per hour, it will be 15 minutes earlier than the driving time. If you walk 18 kilometers per hour, it will be 15 minutes later than the driving time. Now you plan to arrive at the railway station 10 minutes earlier than the driving time, then the speed of the motorcycle should be ()
A. 25km / h B. 26km / h C. 27km / h D. 28km / h

Suppose the distance from motorcycle to railway station is s kilometers, and the time of driving to railway station is t hours. If you walk 30 kilometers per hour, it is 15 minutes earlier than the driving time, then t-s30 = 14. If you walk 18 kilometers per hour, it is 15 minutes later than the driving time, then s18-t = 14

If you travel 30 kilometers per hour, you will arrive 15 minutes earlier; if you travel 20 kilometers per hour, you will be 5 minutes late
If you plan to arrive 5 minutes earlier, how many kilometers per hour should the motorcycle speed be
The prawn helped me answer the O-O

Set the scheduled time to X minutes
30（x-1/4）=20(x+1/12)
30x-15/2=20x+5/3
30x-20x=15/2+5/3
10x=45/6+10/6
10x=55/6
x=11/12
Distance 30x (11 / 12-1 / 4) = 30x2 / 3 = 20km
Speed 20 (11 / 12-1 / 12) = 20 △ 5 / 6 = 24 km / h