#include <iostream>

#include <cstdio>

#include <cstring>

#include <algorithm>

#include <cmath>

using namespace std;

#define N 80050

struct Node

{

	int s,t,id;

	int ans;

}a[N];

int now;

int n,q,block,pos[N],h[N],c[N];

inline bool cmp1(const Node &x,const Node &y)

{

	if(pos[x.s]==pos[y.s]) return x.t<y.t;

	return pos[x.s]<pos[y.s];

}

inline bool cmp2(const Node &x,const Node &y)

{

	return x.id<y.id;

}

void update(int x,int sig)

{

	if(sig==1)

	{

		now+=h[c[x]];

		h[c[x]]++;

	}

	else

	{

		now-=h[c[x]]-1;

		h[c[x]]--;

	}

	/*now-=h[c[x]];

	h[c[x]]+=sig;

	now+=h[c[x]];*/

}

void print(int x)

{

	int b=a[x].ans,d=1ll*(a[x].t-a[x].s)*(a[x].t-a[x].s+1)/2;

	if(b==0)

	{

		puts("0/1");return;

	}

	int gcd=__gcd(b,d);

	printf("%d/%d\n",b/gcd,d/gcd);

}

int main()

{

	scanf("%d%d",&n,&q);

	int i,l,r=0,j;

	for(i=1;i<=n;++i) scanf("%d",&c[i]);

	if(!n)return 0;

	int size=sqrt(n);

	block=n/size;

	for(i=1;i<=block;++i)

	{

		l=r+1;

		r=i*size;

		for(j=l;j<=r;++j)

		{

			pos[j]=i;

		}

	}

	if(r!=n)

	{

		l=r+1;

		r=n;

		block++;

		for(i=l;i<=r;++i)

		{

			pos[i]=block;

		}

	}

	for(i=1;i<=q;++i)scanf("%d%d",&a[i].s,&a[i].t),a[i].id=i;

	sort(a+1,a+q+1,cmp1);

	for(l=1,r=0,i=1;i<=q;++i)

	{

		if(a[i].s==a[i].t)

		{

			a[i].ans=0;

			continue;

		}

		while(l<a[i].s)update(l,-1),l++;

		while(l>a[i].s)update(l-1,1),l--;

		while(r<a[i].t)update(r+1,1),r++;

		while(r>a[i].t)update(r,-1),r--;

		a[i].ans=now;

	}

	sort(a+1,a+q+1,cmp2);

	for(i=1;i<=q;i++)

	{

		print(i);

	}

}