Daddy goes running with his daughter Jana. While Jana ran three times around the small circuit around the school, Daddy ran four times around the larger circuit around the adjacent park. This way, Daddy ran twice the distance Jana did. The small circuit measures 400 meters.

How many meters longer is the large circuit than the small one?

(K. Buzáková)
Jana ran the small circuit three times, which means she ran a total of $3 \cdot 400=1200$ meters.

Daddy ran twice the distance Jana did, which is a total of $2 \cdot 1200=2400$ meters. This distance corresponds to four large circuits; the large circuit measures $2400: 4=600$ meters.

The difference in length between the large and small circuits is $600-400=200$ meters.

Evaluation. 2 points for the results of each paragraph.