#include <iostream>
using namespace std;
//zmienne
float w1,w2;
int a, b, h;
int main()
{
    cout.unsetf ( std::ios::floatfield );
    cin>>h;
    for(int i=0; i<h; i++)
    {
    cin>>a>>b;
    int m=100-a;
    w1=(m-(b*m)/100);
    w2=(100-w1);
    cout.precision(2);
    cout.setf( std::ios::fixed, std:: ios::floatfield );
    cout<<w2<<endl;
    w1=0;w2=0;
    }

    return 0;
}