#include <bits/stdc++.h>
#define pb push_back
#define F first
#define S second
#define sq(x) (x) * (x)
#define ins insert
#define mp make_pair
#define ll long long
#define bit __builtin_popcount
#define all(x) x.begin(),x.end()
#define eb emplace_back
#define ub upper_bound
#define lb lower_bound
#define ios ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
#define er erase

using namespace std;

const int N = 5555, mod = 1e9 + 7;
const double EPS = 1e-7;
const int INF = 2e9;
const int base = 500;
const int dx[] = {1, -1, 0, 0};
const int dy[] = {0, 0, 1, -1};

int x[11111];
main() {
    file("cycle");
    ios;
    int t;
    cin >> t;
    while (t--) {
        int n, a, b;
        cin >> n >> a >> b;
        for (int i = 1; i <= n; ++i) {
            cin >> x[i];
        }
        int num = 0;
        for (int i = 1; i <= n; ++i) {
            for (int j = i + 1; j <= n; ++j) {
                if (x[i] == a && x[j] == b) {
                    ++num;
                }
            }
        }
        int den = n * n;
        int g = __gcd(num, den);
        num /= g;
        den /= g;
        if (num == den || !num) {
            cout << num << "\n";
            continue;
        }
        cout << num << "/" << den << "\n";
    }
    return 0;
}
/// 243368KZ
/**
1 <= T <= 1000
1 <= N <= 10^5
1 <= x <= N
T * N <= 10^7
*/