A car from a to B, planning to travel 40 kilometers per hour, 7.5 hours to arrive, the actual 3 hours to travel 150 kilometers, the actual number of hours to arrive?

A car from a to B, planning to travel 40 kilometers per hour, 7.5 hours to arrive, the actual 3 hours to travel 150 kilometers, the actual number of hours to arrive?

Total distance: 40 × 7.5 = 300 (km)
Actual speed: 150 △ 3 = 50 (km / h)
Actual time: 300 △ 50 = 6 (hours)

A car from a to B, the first two hours of 150km, to find such a speed, and then three hours to reach B, a and B how many kilometers away

Distance between a and B
=150÷2×3+150
=225+150
=375 km

The distance between a and B is 96 kilometers. The express and the local train leave from station a at the same time. One hour later, the express is 12 kilometers ahead of the local train. The express arrives at station B 40 minutes earlier than the local train. What are the speeds of the express and the local train?

40 minutes = 23 hours, let the speed of the slow train be x km / h, and the speed of the fast train be (x + 12) km / h. according to the meaning of the question, 96x-96x + 12 = 23, the solution is: x = 36 or x = - 48 (not suitable for the meaning of the question, rounding off). It will be tested that x = 36 is the solution of the original fractional equation and conforms to the meaning of the question, then 36 + 12 = 48 (km / h). Answer: the speed of the slow train is 36 km / h, and the speed of the fast train is 48 km / h/ Hours