The follwing is my pgm. Could some give a test case not satisfied here?
#include<iostream.h>
#include<math.h>
int main()
{
float p,q,a,b;
int x,a1,b1;
cin>>p>>q;
p/=100;
q/=100;
for(x=1;x<=10000;x++)
{
a=p*x;
b=q*x;
a1=a;
b1=b;
if((float)b1==b)
b1++;
if((float)a1==a)
a1--;
if(abs(b1-a1)==1)break;
}
cout<<x;
return 0;
}

The dude, at me too the fifth test does not go, but if it is interesting to you here my idea and algorithm
My solve
#include <iostream>
#include <cmath>
using namespace std;
int main()
{
#ifndef ONLINE_JUDGE
freopen("1011.in","r",stdin);
freopen("1011.out","w",stdout);
#endif
double p,q;
cin>>p>>q;
p/=100.;
q/=100.;
int n=1,fr=n*p,to=n*q;
while(ceil(n*q)-ceil(n*p) < 1) n++;
cout<<n;
return 0;
}