#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
#include<atcoder/all>
using namespace std;
using namespace atcoder;
using ll=long long;
using ld=long double;

void IO(){
  ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
}

int main(){
  IO();
  ll t;
  cin>>t;
  while(t--){
    ld p;
    cin>>p;
    ll k;
    cin>>k;
    if(p==0){
      cout<<k<<endl;
    }else{
      ld ans=((ld)1-pow((ld)1-p,k))/p;
      cout<<ans<<endl;
    }
  }
}