A is in decimal representation :
Find all naturAls numbers. X , Y.. so that A divide by 25 .
Maybe I am misunderstanding something, I don't know.
so your number can be written:
$\displaystyle A=100\cdot xyxyxyxyx + y5$
where these are the decimal representation.
$\displaystyle 25|100$, so you need only worry about when $\displaystyle 25|y5$ which is clearly only 25 or 75.
so $\displaystyle y=\{2,7\}$
$\displaystyle x=\{0,1,2,3,4,5,6,7,8,9\}$