Thank You it worked for me like this.
I changed my code a bit to the follow code:

# read size of one of these arrays
$count = count($_REQUEST['gender']);
# loop
for($i = 0, $e = 1; $i < $count; $i++, $e++)
{
    $studens.= "Student #{$e}: Gender: $gender[$i]    / Shoe-Size: $shoe_size[$i] / Clothing Size: $clothing_size[$i] / Heigth: $growth[$i]<br />";
}