1-1.pl

#!/usr/bin/perl

use 5.010;

$n=0;
$tally=0;
while ($n < 1000) {

  #print "Number: $n, N-Mod-3: $nmod3, N-Mod-5: $nmod5\n";

  if ($n % 3 == 0) {
    $tally=$tally+$n;
  }
  if ($n % 5 == 0) {
    $tally=$tally+$n;
  }
  if ($n % 5 == 0 && $n % 3 == 0) {
    $tally=$tally-$n;
  }

  $n=$n+1;

}

print "$tally\n";