7.2. In the school gym, there is one arm wrestling table. The physical education teacher organized a school tournament. He calls any two participants who have not yet met each other for a match. There are no draws. If a participant loses twice, they are eliminated from the tournament. After 29 matches were held, all participants were eliminated except for two. How many schoolchildren participated in the tournament
Answer: 16.

Solution: Each participant is eliminated after exactly two losses. In the situation where two "finalists" remain, the total number of losses is 29. If $n$ people have been eliminated from the tournament, then they have collectively suffered $2 n$ losses, while the "finalists" could have $0(0+0), 1(0+1)$ or $2(1+1)$ losses. Considering that $2 n$ and $2 n+2$ are even numbers, we arrive at the equation $2 n+1=29$, from which $n=14$, and the total number of participants is 16.

Comment: A correct answer without justification - 0 points.