Bus route – from point A to point B and back. A bus left point A at a speed of 30 km / h, at point B it turned around

Bus route – from point A to point B and back. A bus left point A at a speed of 30 km / h, at point B it turned around and immediately went back. After 15 minutes from the start of the movement, the bus caught up with the pedestrian, who left point B at the same time as the bus exited from point A. The pedestrian walked at a speed of 6 km / h. Find the distance between points.

Let’s denote the distance from point A to point B by the letter S.
On the road from A to B, the bus, at a speed of 30 km / h, spent S / 30 hours.
Then the bus traveled for another 15 minutes, or 0.25 hours. In total, the bus was on the way (S / 30 + 0.25) hours.
During the same time, the pedestrian covered (S / 30 + 0.25) * 6 kilometers. The bus traveled this distance in 0.25 hours.
We get the equation:
(S / 30 + 0.25) * 6 = 30 * 0.25?
S / 5 + 1.5 = 7.5,
S / 5 = 6,
S = 6 * 5,
S = 30.
Answer: 30 km.