#!/usr/bin/perl
use strict;
use warnings;

<DATA>; #throw way first line

my %ids;  #Hash of Array  "$type $pos" => @ids

while (<DATA>)
{
  my ($id,$type,$pos) = split;
  push @{$ids{"$type $pos"}}, $id; 
}

foreach my $key (sort keys %ids)
{
    next if @{$ids{$key}} == 1;
    
    foreach my $id (@{$ids{$key}})
    {
       print "$id $key\n";
    }
}

=prints:
2 1 11
3 1 11
5 2 5
6 2 5
=cut


__DATA__
ID   Type      Pos
1	1	10
2	1	11
3	1	11
4	1	15
5	2	5
6	2	5
7	2	7