36. The number of students in grades V-VI of one of the schools is expressed by a three-digit number. If you find the product of the digits of this number, and then the product of the digits of the resulting number, then all these three numbers can be written as:

$$
\triangle \bigcirc O ; \triangle \square ; \square
$$

(Identical shapes correspond to identical digits.) How many students are there in grades V-VI in the school?
36. By comparing the numbers $\Delta \square$ and $\square$, we get that $\triangle=1$, because only by multiplying the number $\square$ by 1 do we get the same number $\square$. By comparing 100 and $1 \square$, we get that $\bigcirc=4$, because only by multiplying one by 4 and then again by 4 do we get a number with the tens digit 1. We have $144 ; 1 \cdot 4 \cdot 4=16 ; 1 \cdot 6=6$. In grades V-VI, there are 144 students.