Problem 717

## First solution.

Let's denote the masses of flour, water, and eggs by $x, y$, and $z$, respectively.

The given ratios can be represented as $x: y=7: 2=35: 10$ and $y: z=5: 2=10: 4$, i.e., as the ratio

$$x: y: z=35: 10: 4$$

1 point

Therefore, we can write $x=35 t, y=10 t \text{ and } z=4 t$, where $t$ is a positive real number. 1 point

The total mass is 1470 grams, i.e., $35 t + 10 t + 4 t = 1470$. 1 point

Thus, we have $49 t = 1470$, i.e., $t = 30$.

The total mass of flour is $35 t = 1050 \text{ g}$, water $10 t = 300 \text{ g}$, and eggs $4 t = 120 \text{ g}$.