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diff --git a/challenge-072/wanderdoc/perl/ch-1.pl b/challenge-072/wanderdoc/perl/ch-1.pl
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+++ b/challenge-072/wanderdoc/perl/ch-1.pl
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+#!perl
+use strict;
+use warnings FATAL => qw(all);
+
+=prompt
+You are given a positive integer $N (<= 10).
+Write a script to print number of trailing zeroes in $N!.
+Example 1
+Input: $N = 10 Output: 2 as $N! = 3628800 has 2 trailing zeroes
+Example 2 Input: $N = 7 Output: 1 as $N! = 5040 has 1 trailing zero
+Example 3 Input: $N = 4 Output: 0 as $N! = 24 has 0 trailing zero
+=cut
+
+
+
+
+# Variant #1. A factorial number gets a trailing zero after 4*5 and 9*10.
+use List::Util qw(max);
+
+my %zeroes = (1 => 0, 5 => 1, 10 => 2);
+
+sub find_zeroes_1
+{
+     my ($num, $hr) = @_;
+     return exists $hr->{$num} ? $hr->{$num} : $hr->{max(grep $_ < $num, keys %$hr)};
+
+}
+
+for my $i ( 1 .. 10 )
+{
+     print join("->", $i, find_zeroes_1($i, \%zeroes)), $/;
+}
+
+
+# Variant 2. Calculate factorials for 1 .. 10 (or just save the results in a hash).
+# I could use a factorial subroutine from "Mastering Perl" again :-)
+my %factorials = (1 => 1, 2 => 2, 3 => 6, 4 => 24, 5 => 120,
+6 => 720, 7 => 5040, 8 => 40320, 9 => 362880, 10 => 3628800);
+
+
+sub find_zeroes_2
+{
+     my $num = $_[0];
+
+     my $trailing_zeroes;
+     if ( $num =~ /[^0]([0]+)$/ )
+     {
+          $trailing_zeroes = $1;
+     }
+     return length($trailing_zeroes) || 0;
+}
+
+for ( 1 .. 10 ) 
+{ 
+     print join('->', $_, find_zeroes_2($factorials{$_})), $/; 
+}
+\ No newline at end of file