According to the given statement, let's imagine that the teacher has x students.
He says that if as many students as he has now join his school, it means you add x.
Then a half as many he has, which means you add 1/2x.
Then a quarter as many he has, you add 1/4x.
Finally, if the boy also joins the school, it means you add 1 and obtain a total of 100 students.
Write this in an equation and solve for x:
![\begin{gathered} x+x+(1)/(2)x+(1)/(4)x+1=100 \\ (11)/(4)x+1=100 \\ (11)/(4)x=99 \\ (1)/(4)x=(99)/(11) \\ x=9\cdot4 \\ x=36 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/ofwu0nzuo71cgv80pu31bfhkj4le4oddq0.png)
The teacher has 36 students.