Question 1: A and B walk in opposite directions at the same time at a constant speed. The first encounter was 6 kilometers away from A, and they moved on and returned immediately after reaching the starting point of each other. When they met for the second time at a distance of B 3 kilometers, how many kilometers were A and B apart?

When they met for the first time, * * * did the whole journey, and A did 6 kilometers. When we met for the second time, * * * did the whole journey three times, so A should be able to do it: 6 * 3 = 18km. In fact, A has walked a whole distance plus 3km, so the distance between AB and AB is:18-3 =15km.

Question 2: A and B move in opposite directions at the same time at a constant speed. The first encounter was 6 kilometers away from A, and they moved on and returned immediately after reaching the starting point of each other. When they met for the second time at a distance of A 12 kilometers, how many kilometers were A and B apart? When they met for the first time, * * * did the whole journey, and A did 6 kilometers. When we met for the second time, * * * did the whole journey three times, and A should be able to do it: 6 * 3 = 18km. In fact, A and A have to walk 12km, so the distance between AB and AB is: (18+12)/2 =15km.