#pragma GCC optimize ("O3")
#pragma GCC optimize ("fast-math")
#pragma GCC target ("avx")
#include <bits/stdc++.h>
using namespace std;

const int N = 1 << 16;
const double dx = log(10) / N;
const double ldx = log(log(10)) - 16 * log(2);

double lg[(1 << 17) + 1];

namespace fastio {
    #define getchar getchar_unlocked
    #define putchar putchar_unlocked

    bool dot;

    int readInt() {
        int n, c;
        while ((c = getchar()) < '0') {
            assert(c != EOF);
        }
        n = c - '0';
        while ((c = getchar()) >= '0') {
            n = n * 10 + c - '0';
        }
        dot = c == '.';
        return n;
    }

    void printDouble(double x) {
        int a = x;
        int b = (x - a) * 1e9;
        int d[11];
        int i = 0;
        do {
            d[i++] = a % 10;
            a /= 10;
        } while (a > 0);
        while (i > 0) {
            putchar(d[--i] + '0');
        }
        putchar('.');
        while (i < 9) {
            d[i++] = b % 10;
            b /= 10;
        }
        while (i > 0) {
            putchar(d[--i] + '0');
        }
        putchar('\n');
    }
}

double solve(int a, int b, int c, int d) {
    double lt = lg[c * 10000 + d] - ldx - 4 * log(10);
    if (b == 0) {
        return exp(lt / a);
    }
    if (a == 0) {
        return exp(exp(lt / b));
    }
    int l = 0;
    int r = N;
    while (r - l > 1) {
        int mid = (l + r) / 2;
        (a * mid * dx + b * lg[mid] >= lt ? r : l) = mid;
    }
    double s = (lg[r] - lg[l]) / dx;
    return exp((lt + s * b * l * dx - lg[l] * b) / (s * b + a));

}

int main() {
    for (int i = 0; i <= 1 << 17; i++) {
        lg[i] = log(i) + ldx;
    }
    int m = fastio::readInt();
    for (int i = 0; i < m; i++) {
        int a = fastio::readInt();
        int b = fastio::readInt();
        int c = fastio::readInt();
        int d = fastio::dot ? fastio::readInt() : 0;
        fastio::printDouble(solve(a, b, c, d));
    }
}