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

#define int long long  

using db = long double;

db qpow(db a, int b) {
	db ret = 1.0;
	for (; b; b /= 2, a *= a) {
		if (b % 2) {
			ret *= a;
		}
	}
	return ret;
}

void solve() {
	int n, m, _p;
	cin >> n >> m >> _p;

	db p = 1.0 * _p / 10000;

	auto calc = [&](int x) {
		return 1.0 * (x * n + m) / (1 - qpow(1 - p, x));
	};
	
	int l = 0, r = 1e18;
	while (r - l > 5) {
		int lm = (2 * l + r) / 3;
		int rm = (l + 2 * r) / 3;

		if (calc(lm) < calc(rm)) {
			r = rm;
		} else {
			l = lm;
		}
	}

	db ans = -1;
	for (int i = l; i <= r; i++) {
		if (i <= 0) {
			continue;
		}
		if (ans == -1) {
			ans = calc(i);
		} else {
			ans = min(ans, calc(i));
		}
	}

	cout << ans << "\n";
}

signed main() {  
    ios::sync_with_stdio(false);
    cin.tie(nullptr);  

    cout << fixed << setprecision(10);

    int t;
    cin >> t;
    while (t--) {
    	solve();
    }

    return 0;
}