Towns A and B, a car and a truck drive from towns A and B at the same time. The first encounter is at a distance of 15km from the midpoint. After the encounter, the speed of the truck remains unchanged, and the speed of the car increases (1/5 ), continue driving, the car goes to town B and immediately returns to catch up with the truck, it is 30km away from town A, what is the distance between town A and town B?
甲、乙两镇，一辆轿车和一辆卡车同时从甲、乙两镇相向开出，第一次相遇在距中点15km处，相遇后，卡车车速不变，小轿车提速(1/5)，继续行驶，小轿车走到乙镇后立即返回追上卡车，距甲镇30km处，求甲乙距离？
<result>70</result>