## Task A-1.1.

Ana and Vanja are standing together next to a railway track and waiting for a train that is moving at a constant speed. At the moment when the front of the train reaches them, Ana starts walking at a constant speed in the direction of the train, while Vanja walks at the same speed in the opposite direction. Each of them stops at the moment when the rear of the train passes by her. Ana has walked a total of 45 meters, while Vanja has walked 30 meters. How long is the train?
## First solution.

Notice that Ana walked $45-30=15$ meters more than Vanja, and during the time Ana walked these 15 meters, the train traveled $45+30=75$ meters.

Therefore, the speed of the train is $\frac{75}{15}=5$ times greater than the walking speed.

Notice that while Vanja walked 30 meters, the train traveled $30 \cdot 5=150$ meters in that time.

Since Vanja started walking at the moment the front of the train passed by her, and stopped when the rear of the train passed by, and she was walking in the opposite direction, the total length of the train is $150+30=180$ meters.