Tomatoes were grown in the greenhouse, and some of them were sent for sale, and some were left for seeds.

Tomatoes were grown in the greenhouse, and some of them were sent for sale, and some were left for seeds. How many kilograms of tomatoes were left for seeds, if 72 kg of tomatoes were sent to the store every week, and 300 kg of tomatoes were harvested in just a month?

If there are 4 weeks in a month:
Every week 72 kg are sown, we will find how many tomatoes were sent in total.
72 * 4 = 288 (kg) – no tomatoes were sent.
If a total of 300 tomatoes were collected, and 288 of them were sent, then we will find how many tomatoes were left for seeds. To do this, subtract one from the other.
300 – 288 = 12 (kg)
Answer: 12 kg of tomatoes were left for seeds.

In case there were 5 weeks in a month, it turns out that everything was sent
72 * 5 = 360 kg of tomatoes. Since only 300 kg were collected in total, and this is significantly less than 360, it turns out that such a solution is invalid, because it does not correspond to the condition of the problem.

Final answer: 12 kg.