#include <cstdio>
#include <algorithm>
#include <utility>

using namespace std;

const int N=50001;

struct BIT {
    int a[N];
    int n;
    void clear(int nn) {
        n=nn;
        for (int i=1;i<=n;i++) a[i]=0;
    }
    int lb(int i) {
        return i&-i;
    }
    void set(int i,int x) {
        for (;i<=n;i+=lb(i)) a[i]+=x;
    }
    int get(int i) {
        int ans=0;
        for (;i>0;i-=lb(i)) ans+=a[i];
        return ans;
    }
};

int a[N];
pair<int,int> b[N];
BIT c;
int n,m;

long long gcd(long long a,long long b) {
    while (b) {
        long long c=a%b;
        a=b;
        b=c;
    }
    return a;
}
int main() {
    int t,i,x,y,j;
    scanf("%d",&t);
    while (t--) {
        scanf("%d%d",&n,&m);
        for (i=0;i<n;i++) scanf("%d",&a[i]);
        for (i=0;i<m;i++) {
            scanf("%d%d",&x,&y);
            b[i]=make_pair(x,y);
        }
        sort(b,b+m);
        c.clear(n);
        long long ans=0;
        j=0;
        for (i=0;i<n;i++) {
            while (j<m&&b[j].first<=i+1) {
                c.set(b[j].second,1);
                j++;
            }
            int t=c.get(n)-c.get(i);
            ans+=(long long)t*(t-1)*(t-2)/6*a[i];
        }
        long long ans2=(long long)m*(m-1)*(m-2)/6;
        if (ans2==0) {
            ans=0;
            ans2=1;
        } else {
            long long z=gcd(ans,ans2);
            ans/=z;
            ans2/=z;
        }
        if (ans2==1) printf("%I64d\n",ans);
        else printf("%I64d/%I64d\n",ans,ans2);
    }
    return 0;
}