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

my $wheel = 26.5;
my @chainWheels = qw (42 32 22);
my @cogs =  qw (11 13 15 17 19 21 24 28 32);

print "Wheelsize:   $wheel\n"; 
print "Chainwheels: @chainWheels\n";
print "Sprockets:   @cogs\n\n";

for my $chainSel (1 .. @chainWheels) {
    my $wheelMul = $wheel * $chainWheels[$chainSel - 1];

    print "Chain wheel: $chainSel ratios:  \n";

    for my $cogSel (1 .. @cogs) {
        printf "%d: %5.2f ", $cogSel, $wheelMul / $cogs[$cogSel - 1];
    }
    
    print "\n";
}

##</code><code>##

Wheelsize:   26.5
Chainwheels: 42 32 22
Sprockets:   11 13 15 17 19 21 24 28 32

Chain wheel: 1 ratios:  
1: 101.18 2: 85.62 3: 74.20 4: 65.47 5: 58.58 6: 53.00 7: 46.38 8: 39.75 9: 34.78 
Chain wheel: 2 ratios:  
1: 77.09 2: 65.23 3: 56.53 4: 49.88 5: 44.63 6: 40.38 7: 35.33 8: 30.29 9: 26.50 
Chain wheel: 3 ratios:  
1: 53.00 2: 44.85 3: 38.87 4: 34.29 5: 30.68 6: 27.76 7: 24.29 8: 20.82 9: 18.22