#include <cstring>
#include <cstdio>
#include <algorithm>

using namespace std;
typedef long double ld;

const int MAXN = 55;

int n, col[MAXN], a[MAXN], dep[MAXN], D[MAXN], p[MAXN];
int tot, Last[MAXN], Next[MAXN * 2], Go[MAXN * 2];
ld f[MAXN], c[MAXN][MAXN];

void link(int u, int v) {
    Next[++ tot] = Last[u], Last[u] = tot, Go[tot] = v;
}

void Dfs(int now, int pre) {
    int goal = 0;
    dep[now] = dep[pre] + 1; 
    for (int i = 1; i <= D[0]; i ++) if (dep[now] - dep[D[i]] <= a[D[i]]) goal^= p[D[i]];
    if (col[now] ^ goal == 0) p[now] = 1;
    D[++ D[0]] = now;
    for (int p = Last[now]; p; p = Next[p]) {
        int v = Go[p];
        if (v == pre) continue;
        Dfs(v, now);
    }
    D[0] --;
}

void Solve() {
    memset(f, 0, sizeof f);
    for (int i = n - 1; i >= 0; i --) {
        for (int j = 0; j <= n; j ++) 
            if (i != j) f[i] += c[i][j] * f[j];
        f[i] = (-(f[i] + c[i][n + 1])) / c[i][i];
    }
}

void solve() {
    tot = 0;
    memset(Last, 0, sizeof Last);
    scanf("%d", &n);
    for (int i = 1; i < n; i ++) {
        int u, v;
        scanf("%d%d", &u, &v);
        link(u, v), link(v, u);
    }
    for (int i = 1; i <= n; i ++) scanf("%d", &col[i]);
    for (int i = 1; i <= n; i ++) scanf("%d", &a[i]);
    memset(p, 0, sizeof p);
    Dfs(1, 0);
    memset(c, 0, sizeof c);
    c[n][n] = 1;
    ld nn = (ld)n;
    for (int i = 0; i < n; i ++) c[i][i] = 1;
    for (int i = 0; i < n; i ++) c[i][i + 1] = -(n - i) / nn;
    for (int i = 1; i < n; i ++) c[i][i - 1] = -i / nn;
    for (int i = 0; i < n; i ++) c[i][n + 1] = -1;
     for (int i = 0, j = 0; i <= n && j <= n; j ++) {
        for (int k = i; k <= n; k ++) {
            if (c[k][j]) {
                swap(c[i], c[k]);
                break;
            }
        }
        if (!c[i][j]) continue;
        for (int k = i + 1; k <= n; k ++) {
            if (c[k][j]) {
                ld tt = c[k][j] / c[i][j];
                for (int l = j; l <= n + 1; l ++)
                    c[k][l] = c[k][l] - c[i][l] * tt;
            }
        }
        i ++;
    }
    Solve();
    int num = 0;
    for (int i = 1; i <= n; i ++) if (!p[i]) num ++;
    printf("%.3lf\n", double(f[num]));
}

int main() {
    int t;
    scanf("%d", &t);
    for (int i = 1; i <= t; i ++) solve();
}