#include <map>
#include <set>
#include <queue>
#include <deque>
#include <cmath>
#include <vector>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <unordered_map>
using namespace std;
#define fi first
#define se second
#define u1 (u<<1)
#define u2 (u<<1|1)
#define pb emplace_back()
#define pp pop_back()
#define int long long
#define laile cout<<"laile"<<endl
#define lowbit(x) ((x)&(-x))
#define double long double
#define sf(x) scanf("%lld",&x)
#define sff(x,y) scanf("%lld %lld",&x,&y)
#define sd(x) scanf("%Lf",&x)
#define sdd(x,y) scanf("%Lf %Lf",&x,&y)
#define _for(i,n) for(int i=0;i<(n);++i)
#define _rep(i,a,b) for(int i=(a);i<=(b);++i)
#define _pre(i,a,b) for(int i=(a);i>=(b);--i)
#define all(x) (x).begin(), (x).end()
#define IOS ios::sync_with_stdio(false);cin.tie(0);cout.tie(0)
typedef unsigned long long ULL;
typedef pair<int,int>PII;
typedef pair<double,double>PDD;
const int N=1e6+10,INF=4e18,P=998244353;
int n,m;
int e[N],ne[N],h[N],idx;
int sz[N],sum[N];
int res;
void add(int a,int b)
{
	e[idx]=b;
	ne[idx]=h[a];
	h[a]=idx++;
}
void dfs(int u,int fa)
{
	sz[u]=1;
	sum[u]=0;
	int s=0;
	for(int i=h[u];~i;i=ne[i])
	{
		int j=e[i];
		if(j==fa)continue;
		dfs(j,u);
		sz[u]+=sz[j];
//		sum[u]+=sz[j]*sz[j]%P;
		sum[u]+=sum[j]%P;
		sum[u]%=P;
		res+=2*(n-sz[j])*(n-sz[j])%P*(((sum[j]-sz[j]*sz[j]%P)%P+P)%P)%P;
		res%=P;
		
		res+=sz[j]*(n-sz[j])%P*sz[j]%P*(n-sz[j])%P;
		res%=P;
		s=(s+sum[j])%P;
	}
	
	sum[u]+=sz[u]*sz[u]%P;
	sum[u]%=P;
	

	for(int i=h[u];~i;i=ne[i])
	{
		int j=e[i];
		if(j==fa)continue;
		res+=(sum[j]*(((s-sum[j])%P+P)%P)%P)%P;
		res%=P;
	}
	return;
}
int qmi(int a,int b)
{
	int res=1;
	while(b)
	{
		if(b&1)res=res*a%P;
		a=a*a%P;
		b>>=1;
	}
	return res;
}
void solve()
{
	cin>>n;
	memset(h,-1,(n+1)*8);
	idx=res=0;
	_rep(i,2,n)
	{
		int a,b;
		cin>>a>>b;
		add(a,b);
		add(b,a);
	}
	dfs(1,0);
	int Cn2=n*(n-1)/2;
	Cn2%=P;
	Cn2=Cn2*Cn2%P;
	cout<<"res="<<res<<'\n';
	cout<<res*qmi(Cn2,P-2)%P<<'\n';
	return;
}
signed main()
{
	IOS;
	int T=1;
    cin>>T;
	while(T--)
		solve();
	return 0;
}