13.181. A team of workers was supposed to manufacture 7200 parts per shift, with each worker making the same number of parts. However, three workers fell ill, and therefore, to meet the entire quota, each of the remaining workers had to make 400 more parts. How many workers were in the team?
Solution.

Let there be $x$ workers in the team. Each worker made $\frac{7200}{x}$ parts. After the team size was reduced to $x-3$ workers, each worker started making $\frac{7200}{x}+400$ parts. According to the condition, $\left(\frac{7200}{x}+400\right)(x-3)=7200$, from which $x=9$.

## Answer: 9.