A car goes from place a to place B, two fifths of the whole journey in two hours. At this time, it is 20 kilometers away from the midpoint. How many kilometers are there between a and B?

A car goes from place a to place B, two fifths of the whole journey in two hours. At this time, it is 20 kilometers away from the midpoint. How many kilometers are there between a and B?

20 km is equivalent to 1 / 2-2 / 5 = 5 / 10-4 / 10 = 1 / 10 of the whole journey
The distance between a and B is: 20 ÷ (1 / 10) = 200 km

It takes four fifths of an hour for a car to drive from place a to place B at the same speed. It's already 16 kilometers and it takes one fifths of an hour. I'll give you 100 minutes for the speed

Speed 16 / (1 / 5) = 16 * 5 = 80 km / h

A car from a to B, the first hour of the whole line 1 / 5, the second hour than the first hour more than 15 kilometers, at this time is still far from B
135 km. How long is the highway between a and B?

Sweat From 250 km to 2 / 5 plus 15 km in the first two hours, there are 135 km left. Then the remaining 135 plus 15 is 3 / 5 of the whole journey, that is, the whole journey is 250 km

A road has been repaired for 16 meters, and another 600 meters is just half finished. How long is the road?