13.283. Two pedestrians set out towards each other simultaneously from two points, the distance between which is 28 km. If the first pedestrian had not stopped for 1 hour at a distance of 9 km from the starting point, the meeting of the pedestrians would have taken place halfway. After the stop, the first pedestrian increased their speed by $1 \mathrm{~km} / \mathrm{h}$, and the meeting occurred 4 km from the place where the first pedestrian had stopped. Find the speeds of the pedestrians.
Solution.

Since pedestrians could meet halfway, their speeds are equal. Let $V$ be the initial speed of one of the pedestrians.

According to the condition $\frac{9}{V}+\frac{4}{V+1}+1=\frac{28-(9+4)}{V}$, from which $V=3$ (km/h).

Answer: initially, both were walking at the same speed of 3 km/h.