Two cyclists set off at the same time towards each other from two villages at a distance of 54 km.

Two cyclists set off at the same time towards each other from two villages at a distance of 54 km. The speed of the first is 12 km / h, the second is 15 km / h. In how many hours they will be at a distance of 27 km.

The required unknown number of hours, after which the distance between two cyclists will be 27 kilometers, will be denoted by the conditional variable “Y”.
At the second stage, taking into account the conditions of the example, we compose the equation: Y = (54 – 27) / (12 + 15).
Based on the results of solving this equation, we obtain Y = 27/27 = 1 hour.
Answer: after 1 hour from the start of movement, there will be 27 kilometers between cyclists.