Prof. V.V. Proizvolov

Are there natural numbers $x, y$ and $z$ that satisfy the condition $28 x+30 y+31 z=365$?
In a year, there are 12 months. One of them, February, consists of 28 days, four months (April, June, September, November) consist of 30 days, and the remaining seven months consist of 31 days. Since there are 365 days in a year, $28 \cdot 1 + 30 \cdot 4 + 31 \cdot 7 = 365$.

## Answer

They will be found.