Question 6: A Perl solution 

use WWW::Mechanize;
use XML::LibXML;

my $start_url = 'http://hackoff.apps.mclean.net.nz/spreadsheet/question-001';

my @cols = 'A' .. 'Z';
my @rows =  1  .. 100;
my $cell_data;

my $ua = WWW::Mechanize->new();
$ua->ssl_opts( verify_hostname => 0, SSL_verify_mode => 0x00);
$ua->get($start_url);

foreach my $q (1..110) {
    say "URL: " . $ua->uri;

    open my $fh, '>', 'log.html';
    print $fh $ua->content;
    close($fh);

    my $doc = parse_html($ua->content);
    my $formula = $doc->findvalue(q{//input[@name='formula']/@value})
        or die "Failed to extract formula";
    say "Formula: $formula";

    extract_data($doc);

    my $solution = solve($formula);
    say "Solution: $solution";
    $ua->submit_form(fields => { solution => $solution });
}

# ...