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#include <bits/stdc++.h>
using namespace std;

double Fpow(double x , int n) {
    double res = 1;
    while(n > 0) {
        if(n & 1) res *= x;
        x *= x;
        n >>= 1;
    }
    return res;
}

double x = 5.0 / 0.85786438;  // radius decrease in constant value x 

void solve() {
    cout << fixed << setprecision(8);
    double R; int  n;
    cin >> R >> n;

    cout << R / Fpow(x , n) << '\n';

}
int32_t main() {
    std::ios::sync_with_stdio(false);
    ios_base::sync_with_stdio(false);
    cout.tie(nullptr);
    cin.tie(nullptr);
    int t = 1; cin >> t;
    while (t--)solve();
}