设乙车速度为xkm/h,甲车为(x+10)km/h,两地距离为ykm.由题意得方程组:
[(y/2)/x-(2/3)]*(x+10)=y/2
3x+3(x+10)=y+50
解得:x=30,y=160或x=5,y=10(舍弃)