In a school there are three sports clubs, which we call \(A\), \(B\), and \(C\).
A student argues as follows:
“To find how many people attend at least one club, we can add the number of people in each club. However, students who attend all three clubs get counted three times. To fix this, we should subtract them twice. Therefore, the number of people who attend at least one club is \[\text{people in }A+\text{people in }B+\text{people in }C -2\times(\text{people in all three clubs}).\]”
Is this reasoning correct?