-------inp.txt--------
1	196
1	190
1	200
2	20
3	25
3	19
3	39
4	40
4	41
4	45

##</code><code>##

use strict;
use warnings;

my $in_file = 'inp.txt';

open (IN, $in_file)|| die "couldn't open the in_file\n";

my %r;
while (<IN>)
{
	chomp;
	my $line = $_;
	my @f = split(/\t/, $line);
	
	push(@{ $r{$f[0]} }, $f[1]);
}

close IN;


my @scores =();
my $count;
my $i;
foreach my $key (sort keys %r)
{
	#print "$key\t";
	
	
	@scores = @{ $r{$key} };
	$count = scalar @scores;
	#print "@scores[0..$count]\n";
	
	my $sum = 0;
	#for($i=0; $i <=@scores; $i++)
	for $i (0..$count)
	{
		$sum += $scores[$i];
	}
	
	my $avg = ($sum/$count);
	
	print "$key\t$count\t$avg\n";
	

}