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

// clang-format off
#ifndef NOMACROS

#ifdef LOCAL
#define debug(...) debug_internal(#__VA_ARGS__, __VA_ARGS__)
template <class T, class... Args>
void debug_internal(const char* s, T&& first, Args&&... args)
{
    constexpr const char* open_brakets = sizeof...(args) == 0 ? "" : "(";
    constexpr const char* close_brakets = sizeof...(args) == 0 ? "" : ")";
    cerr << open_brakets << s << close_brakets << ": "
         << open_brakets << std::forward<T>(first);
    ((cerr << ", " << std::forward<Args>(args)), ...);
    cerr << close_brakets << endl;
}
#else
#define debug(x) static_assert(true, "")
#endif // LOCAL

#define GET_MACRO_5(_1, _2, _3, _4, _5, NAME, ...) NAME
#define GET_MACRO_4(_1, _2, _3, _4, NAME, ...) NAME
#define rep(...) GET_MACRO_5(__VA_ARGS__, rep5, rep4, rep3, rep2, rep1)(__VA_ARGS__)
#define rrep(...) GET_MACRO_4(__VA_ARGS__, rrep4, rrep3, rrep2, rrep1)(__VA_ARGS__)
#define rep1(n) rep2(_, n)
#define rep2(i, n) rep3(i, 0, n)
#define rep3(i, a, n) rep4(i, a, n, 1)
#define rep4(i, a, n, d) rep5(i, a, n, d, <)
#define rep5(i, a, n, d, o) for (auto i = remove_reference_t<decltype(n)>(a), _n = (n); i o _n; i += (d))
#define rrep1(n) rrep2(_, n)
#define rrep2(i, n) rrep3(i, n, -1)
#define rrep3(i, a, n) rrep4(i, a, n, 1)
#define rrep4(i, a, n, d) rep5(i, a, n, -d, >)

#define ALL(c) begin(c), end(c)
#define RALL(c) rbegin(c), rend(c)
#define SORT(v) sort(ALL(v))
#define RSORT(v) sort(RALL(v))
#define REV(v) reverse(ALL(v))
#define pb push_back
using ld = long double;
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
template <typename T> using vc = vector<T>;
template <typename T> using vvc = vector<vc<T>>;
using vb = vc<bool>;
using vi = vc<int>;
using vll = vc<ll>;
using vpii = vc<pii>;
using vpll = vc<pll>;
using vs = vc<string>;
using vvb = vvc<bool>;
using vvi = vvc<int>;
void YesNo(bool b) { cout << (b ? "Yes" : "No") << endl; }
template <typename T> inline bool chmax(T &a, T b) { return (a < b) && (a = b, true); }
template <typename T> inline bool chmin(T &a, T b) { return (a > b) && (a = b, true); }

void _cin() {}
template <class Head, class... Tail> void _cin(Head&& head, Tail&&... tail) { cin >> head; _cin(std::forward<Tail>(tail)...); }
#define IN(Type, ...) Type __VA_ARGS__; _cin(__VA_ARGS__)
#define INV(Type, xs, n) vector<Type> xs(n); rep(i, n) cin >> xs[i]
#define INV2(Type, xs, ys, n) vector<Type> xs(n), ys(n); rep(i, n) cin >> xs[i] >> ys[i]
#define INV3(Type, xs, ys, zs, n) vector<Type> xs(n), ys(n), zs(n); rep(i, n) cin >> xs[i] >> ys[i] >> zs[i]
#define INVV(Type, xs, h, w) vector<vector<Type>> xs(h, vector<Type>(w)); rep(i, h) rep(j, w) cin >> xs[i][j]
void OUT() { cout << endl; }
template <class Head, class... Tail> void OUT(Head&& head, Tail&&... tail) { cout << head; if (sizeof...(tail) != 0) cout << endl; OUT(std::forward<Tail>(tail)...); }
template <class Head, class... Tail> void OUTS(Head&& head, Tail&&... tail) { cout << head; if (sizeof...(tail) != 0) cout << " "; OUT(std::forward<Tail>(tail)...); }
template <class Type> void OUT(vector<Type> &vec) { for (auto& a : vec) { cout << a; if (&a != &vec.back()) cout << endl; } }
template <class Type> void OUTS(vector<Type> &vec) { for (auto& a : vec) { cout << a; if (&a != &vec.back()) cout << " "; } cout << endl; }
template <class Type> void OUT(vector<vector<Type>> &df) { for (auto& vec : df) { OUT(vec); } }

struct InitCppIo { InitCppIo() noexcept { cin.tie(nullptr); ios::sync_with_stdio(false); } } initCppIo;

#endif // NOMACROS
// clang-format on

void solve()
{
    IN(double, p);
    IN(int, K);
    ld ans;
    if (p == 0) {
        ans = (ld)K;
    } else {
        ans = (ld)(1 - pow(1 - p, K)) / p;
    }
    OUT(ans);
    return;
}

int main()
{
    cout << fixed << setprecision(10);

    IN(int, T);
    while (T--) {
        solve();
    }
    return 0;
}