If the speed of a car from A to B is increased by 20%, it can arrive 1 hour earlier than the original time; If you drive 80 kilometers at the original speed and the speed is increased by 25%, you can arrive 40 minutes earlier. How many meters is there between A and B?

Solution: After the speed is increased by 20%, it becomes/kloc-0 /× (1+20%) =1.2.

The ratio of original speed to current speed = 1: 1.2 = 5: 6.

Time ratio = 6: 5

Then the original time = 1/( 1-5/6)=6 hours.

Similarly, the speed is increased by 25%.

The ratio of original speed to current speed = 1: 1.25 = 4: 5.

Time ratio = 5: 4

Then the original time after the speed increase = (40/60)/(1-4/5) =10/3 hours.

Then the vehicle speed = 80/(6-10/3) = 80/(8/3) = 30km/h.

So AB distance =30×6= 180 km.

for reference only