It takes 0.5 hours for a garage to travel 30 kilometers, so it travels 60 kilometers per hour.
According to the Y2 diagram, it takes three hours for car B to travel 90km, so it travels 30km per hour.
(1) it takes x hours for car a to catch up with car b 10 km.
60X-30X=30- 10
30X=20
X=2/3
(2) It takes x hours to set up vehicles that exceed the vehicle 10 km.
60X-30X=30+ 10
30X=40
X=4/3
Therefore, the time range when the distance between two cars is not more than10km is 2/3≤X≤4/3.
(3) When car A reaches the finish line, car B moves on. When the second car is away from the finish line 10 km, the distance between the two cars shall not exceed 10 km.
The distance from bus B to the destination is 10 km: (90- 10)÷30=8/3 hours.
Therefore, X≥8/3, and the distance between two vehicles shall not exceed 10 km.
To sum up, 2/3≤X≤4/3 or 8/3≤X≤3.