type    nodd=record
                n,y,d:longint;
        end;

var     a:array[0..1100]of longint;
        b:array[0..1100]of nodd;
        n,t,i,x,tt,k:longint;
        max:double;

procedure init;
begin
        readln(n);
        fillchar(a,sizeof(a),0);
        for i:=1 to n-1 do
        begin
                read(x,b[i].y,b[i].d);
                b[i].n:=a[x]; a[x]:=i;
        end;
end;

procedure dfs(t,s:longint;d:int64);
var     p:longint;
begin
        if t>0 then if d/s>max then max:=d/s;
        p:=a[t];
        while p<>0 do
        begin
                dfs(b[p].y,s+1,d+b[p].d);
                p:=b[p].n;
        end;
end;

procedure work;
begin
        if n=1 then max:=0 else max:=-100000000000;
        dfs(0,0,0);
        writeln(max:0:2);
end;

begin
assign(input,'treec.in');reset(input);
assign(output,'treec.out');rewrite(output);
readln(tt);
for k:=1 to tt do
begin
        init;
        work;
end;
close(input);close(output);
end.