If the speed of a car from a to B increases by 20%, it can be 1 hour earlier than the original time. If the speed is 5 kilometers faster than the original time, it can save 1 / 9 of the time. Then how many kilometers is the distance between a and B?

If the speed of a car from a to B increases by 20%, it can be 1 hour earlier than the original time. If the speed is 5 kilometers faster than the original time, it can save 1 / 9 of the time. Then how many kilometers is the distance between a and B?

The distance is fixed, and the speed is inversely proportional to the time
If the vehicle speed increases by 20 ℅
Speed after increase: original speed = (1 + 20 ℅): 1 = 6:5
Time to increase speed: original time = 5:6
Original scheduled time = 1 ÷ (6-5) × 6 = 6 hours
If you speed up 5 kilometers per hour, you can save 1 / 9 of the time
Time after speeding up: original time = (1-1 / 9): 1 = 8:9
Speed up: original speed = 9:8
Original speed = 5 ÷ (9-8) × 8 = 40 km / h
Distance between a and B = 6 × 40 = 240 km