$15, $1/chocolate, 3 wrappers/chocolate, find max

<?php

// You can run this code at http://writecodeonline.com/php/

$dollars = 1502;

$cost = 3; // Dollars per chocolate
$ratio = 3; // Wrappers to receive another chocolate

$chocolates = $wrappers = floor($dollars / $cost);

while ($wrappers >= $ratio)
{
        $wrappers = $wrappers - $ratio + 1;
        $chocolates++;
}

echo "$" . $dollars . " gets you " $chocolates . " chocolates with " . $wrappers . " wrapper(s) and $" . $dollars % $cost . " left over.";

// Example Output:
// $1502 gets you 749 chocolates with 2 wrapper(s) and $2 left over.

?>