1 /* 2 ━━━━━┒ギリギリ♂ eye！ 3 ┓┏┓┏┓┃キリキリ♂ mind！ 4 ┛┗┛┗┛┃＼○／ 5 ┓┏┓┏┓┃ / 6 ┛┗┛┗┛┃ノ) 7 ┓┏┓┏┓┃ 8 ┛┗┛┗┛┃ 9 ┓┏┓┏┓┃10 ┛┗┛┗┛┃11 ┓┏┓┏┓┃12 ┛┗┛┗┛┃13 ┓┏┓┏┓┃14 ┃┃┃┃┃┃15 ┻┻┻┻┻┻16 */17 #include <algorithm>18 #include <iostream>19 #include <iomanip>20 #include <cstring>21 #include <climits>22 #include <complex>23 #include <fstream>24 #include <cassert>25 #include <cstdio>26 #include <bitset>27 #include <vector>28 #include <deque>29 #include <queue>30 #include <stack>31 #include <ctime>32 #include <set>33 #include <map>34 #include <cmath>35 using namespace std;36 #define fr first37 #define sc second38 #define cl clear39 #define BUG puts("here!!!")40 #define W(a) while(a--)41 #define pb(a) push_back(a)42 #define Rint(a) scanf("%d", &a)43 #define Rs(a) scanf("%s", a)44 #define Cin(a) cin >> a45 #define FRead() freopen("in", "r", stdin)46 #define FWrite() freopen("out", "w", stdout)47 #define Rep(i, len) for(int i = 0; i < (len); i++)48 #define For(i, a, len) for(int i = (a); i < (len); i++)49 #define Cls(a) memset((a), 0, sizeof(a))50 #define Clr(a, x) memset((a), (x), sizeof(a))51 #define Full(a) memset((a), 0x7f7f7f, sizeof(a))52 #define lrt rt << 153 #define rrt rt << 1 | 154 #define pi 3.1415926535955 #define RT return56 #define lowbit(x) x & (-x)57 #define onecnt(x) __builtin_popcount(x)58 typedef long long LL;59 typedef long double LD;60 typedef unsigned long long ULL;61 typedef pair<int, int> pii;62 typedef pair<string, int> psi;63 typedef pair<LL, LL> pll;64 typedef map<string, int> msi;65 typedef vector<int> vi;66 typedef vector<LL> vl;67 typedef vector<vl> vvl;68 typedef vector<bool> vb;69 70 const int maxn = 100100;71 LL n;72 LL w, w2;73 LL K, B;74 75 LL gcd(LL x, LL y) {76     return y == 0 ? x : gcd(y, x%y);77 }78 79 int main() {80     // FRead();81     int T;82     Rint(T);83     W(T) {84         Rint(n);85         K = B = 0;86         For(i, 1, n+1) {87             cin >> w;88             w2 = w * w;89             B += abs(w);90             K += w2;91         }92         LL p = n * K - B * B;93         LL ex = gcd(p, n);94         cout << p/ex << "/" << n/ex << endl;95     }96     RT 0;97 }