Car 3 meets car 1 at Q, which is 200km from A. Therefore, at the time of their meeting car 1 must have travelled 200km and car 3 must have travelled 100km. As the time is same, ratio of speed of car 1 to speed of car 3=2:1. Car 3 meets car 2 at P, which is 100km from A. Therefore, at the time of their meeting car 2 must have travelled 100km and car 3 must have travelled 200km. As the time is same, ratio of speed of car 2 to speed of car 3=1:2. Speed of car 1: speed of car 3=2:1 And speed of car2: speed of car3=1:2 So, speed of car 1: speed of car 2: speed of car 3=4:1:2