use strict;
use warnings;
my @entity = (
    35000,
    41000,
    16000,
    18000,
    21000,
    45000,
    27000,
    10000,
    16000,
);

my( @sample ) = @entity{ 8, 8, 3, 1, 5, 0, 0 };

my $prob = probability( \@entity, \@sample );

##</code><code>##

sub probability {
    my $entity_count = @{$_[0]};
    my $sample_count = @{$_[1]};
    return( ( 1 / $entity_count ) ^^ $sample_count );
}