#include<cstdio>

 #include<cstring>

 #include<algorithm>

 #include<cstdlib>

 #include<iostream>

 #include<cmath>

 using namespace std;

 typedef long long ll;

 ll n,m,ans;

 struct node{

     ll l,r,id;

 }b[];

 struct nd{

     ll a,b;

 }as[];

 ll a[],pos[],s[];

 bool cmp1(const node &a,const node &b){

     return ((pos[a.l]==pos[b.l])&&(a.r<b.r))||(pos[a.l]<pos[b.l]);

 }

 void init(){

     ll block=sqrt(n);

     for(int i=;i<=n;i++) pos[i]=(i-)/block+;

 }

 void update(ll p,ll add){

     /*ans-=s[a[p]]*s[a[p]];

     s[a[p]]+=add;

     ans+=s[a[p]]*s[a[p]];*/

     ans+=*add*s[a[p]]+(add==?:);

     s[a[p]]+=add;

 }

 void solve(){

     for(int i=,l=,r=;i<=m;i++){

         for(;r<b[i].r;r++)  update(r+,);

         for(;r>b[i].r;r--)  update(r, -);

         for(;l<b[i].l;l++)  update(l, -);//这里注意搞清楚

         for(;l>b[i].l;l--)  update(l-,);

         if(b[i].l==b[i].r){

             as[b[i].id].a=,as[b[i].id].b=;//题目要求

             continue;

         }

         ll c=ans;

         ll d=(b[i].r-b[i].l+)*(b[i].r-b[i].l);

         ll k=__gcd(c,d);

         c/=k,d/=k;

         as[b[i].id].a=c,as[b[i].id].b=d;

     }

 }

 int main(){

     cin>>n>>m;

     for(int i=;i<=n;i++) cin>>a[i];

     for(int i=;i<=m;i++){

         cin>>b[i].l>>b[i].r;

         b[i].id=i;

     }

     init();

     sort(b+,b+m+,cmp1);

     solve();

     for(int i=;i<=m;i++){

         cout<<as[i].a<<"/"<<as[i].b<<"\n";

     }

 }