/* 數學 */ #include #include #include using namespace std; double power(double base, int exponential) { if (exponential == 0) return 1; else if (exponential == 1) return base; double ans = power(base, exponential / 2); if (exponential & 1) return ans * ans * base; return ans * ans; } int main() { cin.tie(0); ios_base::sync_with_stdio(0); int n_testcase; cin >> n_testcase; while (n_testcase--) { int n_people, index; double probability; cin >> n_people >> probability >> index; double q = 1 - probability; double common_ratio = power(q, n_people); if (common_ratio == 1) cout << "0.0000\n"; else cout << setprecision(4) << fixed << power(q, index - 1) * probability / (1 - common_ratio) << "\n"; } }