## 203. Math Puzzle $4 / 82$

During a vacation trip with a car, the odometer shows the following symmetrical number: $36463 \mathrm{~km}$.

After two hours of driving, the next symmetrical number appears. At what average speed did the car travel?
The next symmetrical number on the odometer appears after the change of the hundreds digit. So the old reading was 36463, the new reading is 36563.

In the two hours, the car traveled $100 \mathrm{~km}$, so the speed was $50 \mathrm{~km} / \mathrm{h}$.