#include <iostream>
using namespace std;
int main()
{
        int _T; scanf("%d", &_T);
        while(_T--) {
                int W, B, C; scanf("%d %d %d", &W, &B, &C);
                if(C == 1) {
                        printf("%.3llf\n", ((long double)W)/(W+B));
                } else if(W == 0) {
                        printf("0.000\n");
                } else {
                        if(W < C) {
                                printf("%.3llf\n", ((long double)W)/C);
                        } else {
                                long double first = ((long double)(C-1))/C;
                                long double second = ((long double)(W-C+1));
                                long double third = ((W-C+1+B)*C);
                                printf("%.3llf\n", first+second/third);
                        }
                }
        }
        return 0;
}