#include <bits/stdc++.h> using namespace std; #define ALL(i_) i_.begin(), i_.end() #define PB push_back #define TASK "" typedef long long ll; typedef long double ld; typedef pair<int, int> ii; const int oo = 1000000099; const int mod = 1000000007; const int maxn = 100011; int ntest; ld res[maxn]; int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); if (fopen(TASK ".inp", "r")) { freopen(TASK ".inp", "r", stdin); freopen(TASK ".out", "w", stdout); } cin >> ntest; while (ntest--) { ld x; int n; cin >> x >> n; ld cur = x; ld res = x; for (int i = 2; i <= n; i++) { cur *= (x / (1.0 * i)); res += cur; } cout << setprecision(5) << fixed << res << "\n"; } return 0; }