Question

In a school auditorium, the number of chairs in a row is the same as the number of rows of chairs. There are 3948 students in the school. If we know that less than 22 chairs were empty, how many chairs were empty after all the students sat down?

Answer 1

`x^2-21=3948`
`x^2=3969`
`x=sqrt3969`
`x=63`
21 chairs will left after sitting the student.