1、Use extended,not real,and you'll get AC.
If you want to know why,you can readln some real like 100/100 and use WATCH to check it in the program.You may find that the number change to someting like"1.0000000001"or"0.99999999998".

2、Take care of the description:less than q%.Less than!!!!
So:if trunc((i*q/100))=(i*q/100) then continue;

use integer, not float
then EPS = 1/50000 (if p = P*500, q = Q*500, else if for p and q to take a multiplier smaller, for example 200 and to divide on 20000, we will receive WA 22 (40 -> WA 23))