2. On the first day, Masha collected $25 \%$ fewer berries than Vanya, and on the second day, $20 \%$ more than Vanya. Over the two days, Masha collected $10 \%$ more berries than Vanya. What is the smallest number of berries they could have collected together?
# Solution

Masha collected $3 / 4$ on the first day and $-6 / 5$ of the number of berries collected by Vanya over these days. Let Vanya collect $4 x$ berries on the first day and $5 y$ on the second day, then Masha collected $3 x$ and $6 y$ berries respectively. According to the condition, $3 x + 6 y = 11 / 10 (4 x + 5 y)$. This equality can be easily transformed into $14 x = 5 y$. Now it is clear that $x$ is a multiple of 5, and $y$ is a multiple of 14, so the smallest natural numbers satisfying this equality are: $x = 5, y = 14$, and the total number of berries is $21 / 10 (4 x + 5 y) = 189$.

Answer: 189 berries