#include<bits/stdc++.h>
#define int long long
using namespace std;
int T;
double n,m,p;
double qpow(double a,int x)
{
	double ans=1;
	while(x)
	{
		if(x&1)
		{
			ans=(ans*a);
		}
		a=(a*a);
		x>>=1;
	}
	return ans;
}
int check(double x)
{
	double py=-n/(x*log(p)),y=log(py)/log(p);
	double y1=floor(y),y2=ceil(y);
	if(y1>=1&&y1*n+m+x*(qpow(p,(int)y1)-1)<=0)
	{
		return 1;
	}
	if(y2>=1&&y2*n+m+x*(qpow(p,(int)y2)-1)<=0)
	{
		return 1;
	}
	if(n+m+x*(p-1)<=0)
	{
		return 1;
	}
	return 0;
}
void solve()
{
	scanf("%lf%lf%lf",&n,&m,&p);
	p=1-p/10000;
	double l=0,r=1e18+7;
	while(r-l>1e-8)
	{
		double mid=(l+r)/2.0;
		if(check(mid))
		{
			r=mid;
		}
		else
		{
			l=mid;
		}
	}
	double ans=(l+r)/2.0;
	printf("%.12lf\n",ans);
}
signed main()
{
	cin>>T;
	while(T--)
	{
		solve();
	}
	return 0;
}