7. In a cafe, three friends met: sculptor Belov, violinist Chernov, and artist Ryzhov. "It's great that one of us has white, one has black, and one has red hair, but none of us has hair of the color that our last name suggests," noted the black-haired man. "You're right," — said Belov. What color is the artist's hair?
7. This problem can be solved through reasoning or using the tabular method.

The first solution method. Belov was talking to the black-haired person, which means his hair color is neither black nor white (due to the fact that the hair color should not indicate the surname). Therefore, Belov has red hair. Since Belov was talking to the black-haired person, he could not be Chernov, so he must have been Ryzhov. Thus, the artist Ryzhov had black hair.

The second solution method. This problem involves three friends (Belov, Ryzhov, Chernov) and three hair colors (white, red, black). Let's create a table:

|  | w | r | b |
| :--- | :--- | :--- | :--- |
| B |  |  |  |
| R |  |  |  |
| C |  |  |  |

Given that none of the friends have hair of the color that their surname suggests, we can fill in the table:

|  | w | r | b |
| :--- | :--- | :--- | :--- |
| B | - |  |  |
| R |  | - |  |
| C |  |  | - |

Belov was talking to a person with black hair. Therefore, Belov did not have black hair.

|  | w | r | b |
| :--- | :--- | :--- | :--- |
| B | - |  | - |
| R |  | - |  |
| C |  |  | - |

Thus, Belov had red hair.

|  | w | r | b |
| :--- | :--- | :--- | :--- |
| B | - | + | - |
| R |  | - |  |
| C |  |  | - |

Therefore, Chernov could not have red hair.

|  | w | r | b |
| :--- | :--- | :--- | :--- |
| B | - | + | - |
| R |  | - |  |
| C |  | - | - |

Analyzing the table allows us to conclude that Chernov had white hair, which means Ryzhov had black hair.

|  | w | r | b |
| :--- | :--- | :--- | :--- |
| B | - | + | - |
| R | - | - | + |
| C | + | - | - |

Answer: The artist Ryzhov has black hair.

## SIXTH