## Task A-2.1.

The students decided to play a game with a total of 960 tokens. First, they divided all the tokens equally so that each of them had the same number of tokens. As soon as they did this, their teacher arrived and wanted to join the game. Each student gave the teacher 4 tokens, so everyone had an equal number of tokens and they were ready to start the game. How many students are participating in the game?
## First solution.

Let $n$ be the number of students.

According to the problem statement, the teacher received $4 n$ tokens,

1 point

and the same amount remained for each student.

This means that at the beginning, each student had $4 n+4$ tokens, 1 point

and the total number of tokens is $n(4 n+4)=960$, so $n(n+1)=240$. 1 point

The solutions to the obtained quadratic equation are $n_{1}=-16, n_{2}=15$. 1 point

Since $n$ must be a natural number, the only possibility is $n=15$. 1 point

There are 15 students participating in the game.