#include<bits/stdc++.h>
using namespace std;
typedef long double ld;
ld dp[20][1<<18],ans[20][111],p;
bool vis[20][1<<18];
int num[1<<18];
ld solve(int n,int mask){
    if(num[mask]>=n)return 0;
    if(vis[n][mask])return dp[n][mask];
    dp[n][mask]=0;
    vis[n][mask]=1;
    //2
    int nmask=mask+1;
    dp[n][mask]=(1-p)*(solve(n,nmask)+2*((mask^nmask)-1));
    //4
    if(mask%2){
        dp[n][mask]+=p*(solve(n-num[mask],2));
    }
    else {
        nmask=mask+2;
        dp[n][mask]+=p*(solve(n,nmask)+2*((mask^nmask)-2));
    }
    return dp[n][mask];
}
void all(){

    for(int i=0;i<=100;++i){
        p=i;p/=100;
        memset(vis,0,sizeof vis);
        for(int n=1;n<17;++n){
            for(int j=2*(1<<n)-1;j>0;--j)solve(n,j);
            ans[n][i]=solve(n,0);
        }
    }
}
int main()
{
    for(int i=0;i<(1<<18);++i)num[i]=__builtin_popcount(i);
    all();
    int t;
    cin>>t;
    while(t--){
        int n,x;
        cin>>n>>x;
        cout<<setprecision(6)<<fixed<<ans[n][x]<<endl;
    }
}