7.2. In a family, there are three brothers. It is known that Kolya was born the year after the year when there were 5 years left until the birth of the youngest of the brothers, and Vanya was born two years earlier than when the middle one turned 3 years old. Now Petya is 10 years old. How old are Vanya and Kolya?
Answer: Vanya is now 9 years old, and Kolya is 13 years old.

Solution: From the second condition about Vanya, it follows that he is 1 year younger than the middle brother, so Vanya is the youngest. Kolya is 4 years older than the youngest, so he is the oldest. Therefore, Petya is the middle one, which means Vanya is now 9 years old, and Kolya is 13 years old.