If the speed of a car from place a to place B is increased by 20%, it can arrive one hour earlier than the original time. If it travels at the original speed of 100 km, it can arrive again If you increase the speed by 30%, you will arrive one hour earlier than the original time. What is the distance between a and B?

If the speed of a car from place a to place B is increased by 20%, it can arrive one hour earlier than the original time. If it travels at the original speed of 100 km, it can arrive again If you increase the speed by 30%, you will arrive one hour earlier than the original time. What is the distance between a and B?

Assuming that the original speed is x km / h and the original time is t h, there are two equations: XT = (1 + 20%) x * (t-1), 100 / x + (xt-100) / (1 + 30%) x = T-1; solving these two equations, we can get x = 60 t = 6; therefore, the distance between a and B is 60 * 6 = 360 km

If the speed of a car from a to B increases by 20%, it can arrive one hour earlier than the original time; if it runs 80 km from the original speed, it can arrive 40 minutes earlier. What is the distance between a and B?

∵ speed increased by 20% to 6 / 5 of the original,
The time required is 5 / 6 of the original, increased by 1 / 6,
∵ increase by 1 hour, ∵ originally need 1 △ 1 / 6 = 6 (hours)
If the original speed is x, the distance between a and B is 6x,
We can get (6-80 / X-2 / 3) * 5x / 4 + 80 = 6x,
The solution is x = 30,
30*6=180
The distance between a and B is more than 180 km