my %master = (
 Alex => [ [3,44], [124,175] ],
 Barry => [ [2,44] ],
 # more data here #
);

##</code><code>##

my $some_name = 'Alex';
foreach my $range ( @{$master{$some_name}} ){
  my ($start, $end) = @$range;
  print "$start, $end\n";
}