#include <bits/stdc++.h>
 
using namespace std;
 
const int MaxN = (int)1e5 + 10;
const int MOD = (int)1e9 + 7;
const long long INF = 1e14;

typedef long double dbl;

struct Point {
	dbl x, y, z;
	Point(dbl _x = 0.0, dbl _y = 0.0, dbl _z = 0.0) :
		x(_x), y(_y), z(_z) {
	}
	dbl dist(const Point &o) const {
		return sqrtl((x - o.x) * (x - o.x) +
						(y - o.y) * (y - o.y) +
						(z - o.z) * (z - o.z));
	}
	void read() {
		cin >> x >> y >> z;
	}
};

dbl checkInside(const Point &centre, const Point &o, dbl r) {
	return centre.dist(o) <= r;
}

bool visible(const Point &a, const Point &b, const Point &c, dbl rad) {
	dbl l = 0, r = 1, res = 0;
	for (int it = 0; it < 80; ++it) {
		dbl ll = l + (r - l) / 3.0;
		dbl rr = r - (r - l) / 3.0;
		Point fl = Point(a.x + ll * (b.x - a.x),
							a.y + ll * (b.y - a.y),
							a.z + ll * (b.z - a.z));
		Point fr = Point(a.x + rr * (b.x - a.x),
							a.y + rr * (b.y - a.y),
							a.z + rr * (b.z - a.z));
		dbl ul = c.dist(fl), ur = c.dist(fr);
		if (ul < ur) {
			r = rr;
			res = ur;
		} else {
			l = ll;
			res = ul;
		}
	}
	return res <= rad;
}

void solve() {
	Point p1, p2, dir, centre;
	dbl rad;
	p1.read();
	p2.read();
	dir.read();
	centre.read();
	cin >> rad;
	dbl l = 0, r = 2e9; 
	for (int it = 0; abs(r - l) > 1e-7; ++it) {
		dbl t = (l + r) / 2.0;
		Point p20 = Point(p2.x + dir.x * t, 
							p2.y + dir.y * t, 
							p2.z + dir.z * t);
		if (visible(p1, p20, centre, rad)) {
			l = t;
		} else {
			r = t;
		}
	}
	cout.precision(10);
	cout << fixed << (l + r) / 2.0 << "\n";
}

int main() {
//	freopen("input.txt", "r", stdin);
	ios::sync_with_stdio(false); cin.tie(NULL);
	int t;
	cin >> t;
	assert (1 <= t && t <= 1e5);
	while (t --> 0) {
		solve();
	}
	return 0;
}