var a,b:array[0..1000,0..1000]of longint;
    f,g:array[0..1000]of longint;
    p:array[1..10000]of longint;
    i,k,n,now,x,y,z,t:longint;
    head,tail:longint;
    temp:real;

begin
 assign(input,'treec.in');reset(input);
 assign(output,'treec.out');rewrite(output);
 readln(t);
 for k:=1 to t do
  begin
   readln(n);
   fillchar(b,sizeof(b),0);
   fillchar(a,sizeof(a),0);
   for i:=1 to n-1 do
    begin readln(x,y,z);inc(b[x,0]);b[x,b[x,0]]:=y;a[x,y]:=z;end;
   p[1]:=0;head:=0;tail:=1;f[0]:=0;g[0]:=0;
   while head<>tail do
    begin
     inc(head);
     now:=p[head];
     for i:=1 to b[now,0]do
      begin
       f[b[now,i]]:=f[now]+a[now,b[now,i]];
       g[b[now,i]]:=g[now]+1;
       inc(tail);p[tail]:=b[now,i];
      end;
    end;
   temp:=0;
   for now:=1 to n-1 do if f[now]/g[now]>temp then temp:=f[now]/g[now];
   writeln(temp-1:0:2);
  end;
 close(output);
end.