This is a typical problem in primary school mathematics: it is called three application problems. In other words, when they met for the second time, they went to AB three times. (You can tell by drawing a picture)

The first meeting was 60 kilometers away from a place, that is to say, it is feasible for A to walk 60 kilometers. After two encounters, they walked three full distances, and A * * * walked 60 * 3 =180km.

The second time is 40 kilometers away from point A, 180+40 = 220 kilometers, which happens to be the whole journey from A to B and back to A, that is, 220/2 = 1 100 kilometers. Is the distance of AB.

1 10-60 = 50 is the answer to the question.