## 154. Math Puzzle 3/78

During a traffic check in a closed town, a motorcyclist covered the $100 \mathrm{~m}$ long test track in a time of $6 \mathrm{~s}$.

Does his speed comply with the regulations of the Road Traffic Ordinance?
The speed of the motorcyclist on the test track is:

$$
v=\frac{s}{t}=\frac{100 \mathrm{~m}}{6 \mathrm{~s}}=16.7 \frac{\mathrm{m}}{\mathrm{s}}=60 \frac{\mathrm{km}}{\mathrm{h}}
$$

In a closed residential area, only a speed of $50 \mathrm{~km} / \mathrm{h}$ is permitted if the road is not marked as a motorway. The motorcyclist exceeded the speed limit and thereby endangered other road users (Section 12 and § 1 of the Road Traffic Regulations).