#include <bits/stdc++.h>
using namespace std;
#define IOS ios::sync_with_stdio(0), cin.tie(0), cout.tie(0)
#define endl '\n'
const int N = 2e5 + 5;
#define int long long
typedef pair<int, int> PII;
#define MAX LONG_LONG_MAX
#define mod 10007
#define eps 1e-7
int a, b;
double p;

double calc(double mid)
{
    return ((double)a * mid + b) / (1 - pow(1 - p * 1e-4, mid));
}
void solve()
{
    cin >> a >> b >> p;
    double l = 1, r = 1e9;
    while (r - l > 1e-8)
    {
        double lmid = l + (r - l) / 3.0;
        double rmid = r - (r - l) / 3.0;

        double x = calc(lmid), y = calc(rmid);
        if (x < y)
            r = rmid;
        else
            l = lmid;
    }
    int x = round(l);
    if (calc(x) > calc(x - 1))
        x--;
    if (calc(x + 1) < calc(x))
        x++;

    printf("%.10lf\n", calc(x));
}

signed main()
{
    int t;
    cin >> t;
    while (t--)
        solve();

    return 0;
}