# Points A and B are connected by a highway, on each meter of which, starting from point A

**Points A and B are connected by a highway, on each meter of which, starting from point A and ending with point B, there are pillars with a plate on which the distances from this pillar to point A and B are indicated.The sum of all the numbers on each plate is 13. Which is equal to highway length?**

To solve the proposed problem, consider a practical example.

Let the distance between cities A and B be x kilometers. Then on the pillar, which is located 1 km from the city A, two numbers will be written: “1” (because to the city A is 1 km) and “x – 1” (because to the city B is 1 km less than the distance between A and B). The second column will say “2” and “x – 2” and so on.

Therefore, the sum of the digits on the pillars will be:

1 + x – 1 = x;

2 + x – 2 = x, etc.

Therefore, the distance between A and B is 13 km.