Aldo, Bernardo, and Carlos play cards. At the beginning, the amount of money they had was in the ratio $7: 6: 5$. At the end of the game, the ratio was $6: 5: 4$. One of the players won 1200 reais. What is the amount of money each player ended up with, at the end of the game?
Let $T$ be the total amount of money in the game. Thus, at the beginning, the players had:

$$
\begin{array}{ll}
\text { Aldo: } & \frac{7}{18} T \\
\text { Bernardo: } & \frac{6}{18} T \\
\text { Carlos: } & \frac{5}{18} T
\end{array}
$$

At the end, they had:

$$
\begin{array}{ll}
\text { Aldo: } & \frac{6}{15} T \\
\text { Bernardo: } & \frac{5}{15} T \\
\text { Carlos: } & \frac{4}{15} T
\end{array}
$$

To better compare these fractions, let's put them with a common denominator:

At the beginning:

$$
\begin{array}{llrl}
\text { Aldo: } & & \frac{7}{18} T & =\frac{35}{90} T \\
& \text { Bernardo: } & \frac{6}{18} T & =\frac{30}{90} T \\
\text { Carlos: } & & \frac{5}{18} T & =\frac{25}{90} T .
\end{array}
$$

At the end:

$$
\begin{aligned}
& \text { Aldo: } \quad \frac{6}{15} T=\frac{36}{90} T \\
& \text { Bernardo: } \quad \frac{5}{15} T=\frac{30}{90} T \\
& \text { Carlos: } \quad \frac{4}{15} T=\frac{24}{90} T
\end{aligned}
$$

Thus, Carlos lost $1/90$ of the total, and Aldo won $1/90$. Therefore, 1220 corresponds to $1 / 90$ of the total amount of money. Therefore, the total $T$ of money at the beginning of the game is:

$$
\frac{1}{90} T=1200 \Rightarrow T=90 \times 1200=108000
$$

Thus, at the end of the game, the players had:

Aldo: $\quad \frac{35}{90}$ of $108000=42000$

Bernardo: $\quad \frac{30}{90}$ of $108000=36000$

Carlos: $\quad \frac{25}{90}$ of $108000=30000$.