#include<cstdio>
#include<cmath>
#include<algorithm>
using namespace std;
typedef long long ll;
const int maxn=50000+100;
inline ll gcd(ll a,ll b){
return b==0?a:gcd(b,a%b);
}
ll ans;
int R[maxn],num[maxn],col[maxn];
struct Mo{
int l,r;
int id;
ll A,B;
}mo[maxn];
inline bool cmp(Mo a,Mo b){
return R[a.l]==R[b.l]?a.r<b.r:a.l<b.l;
}
inline bool CMP(Mo a,Mo b){
return a.id<b.id;
}
inline void kaven(int ind,int v){
ans-=(ll)num[col[ind]]*num[col[ind]];
num[col[ind]]+=v;
ans+=(ll)num[col[ind]]*num[col[ind]];
}
int main(){
int n,m;
scanf("%d%d",&n,&m);
int tmp=sqrt(n);
for(int i=1;i<=n;i++) scanf("%d",&col[i]),R[i]=i/tmp+1;
for(int i=1;i<=m;i++){
scanf("%d%d",&mo[i].l,&mo[i].r);
mo[i].id=i;
}
sort(mo+1,mo+m+1,cmp);
int l=1;
int r=0;
for(int i=1;i<=m;i++){
while(l<mo[i].l) kaven(l,-1),l++;
while(l>mo[i].l) kaven(l-1,1),l--;
while(r<mo[i].r) kaven(r+1,1),r++;
while(r>mo[i].r) kaven(r,-1),r--;
if(mo[i].l==mo[i].r){
mo[i].A=0;
mo[i].B=1;
continue;
}
ll tmpe=(mo[i].r-mo[i].l+1);
mo[i].A=ans-tmpe;
mo[i].B=tmpe*(tmpe-1);
ll GCD=gcd(mo[i].A,mo[i].B);
mo[i].A/=GCD;
mo[i].B/=GCD;
}
sort(mo+1,mo+m+1,CMP);
for(int i=1;i<=m;i++){
printf("%lld/%lld\n",mo[i].A,mo[i].B);
}
}
