# Task 1.

The pedestrian's speed is 5 km/h. There are more oncoming trams than overtaking ones, because the speed of the former relative to the pedestrian is greater than that of the latter. If we assume that the pedestrian is standing still, the speed of the oncoming trams is the sum of the tram's own speed $V+$ the pedestrian's speed. Therefore, the relative speed of the oncoming trams is $V+5$, and the relative speed of the overtaking trams is $V-5$. It is clear that the number of trams passing a given point in a certain time is proportional to their speed, from which we have the equation:

$$
\frac{V+5}{V-5}=\frac{600}{225} \rightarrow V=11 \text { km } / \text { hour. }
$$
Answer: $11 \mathrm{km} /$ hour.