@car_prices = (100, 250, 95, 1300, 4534, 102, 100, 97);
@flight_prices = (85.20, 79.99, 45.30, 130, 45.34, 110.25, 100, 917);
# define subroutines
sub min {
    $current_min = $_[0];
    foreach $number (@_) {
        if ($number < $current_min) {
            $current_min = $number;
        }
    }
    return($current_min);
}
sub max {
    $current_max = $_[0];
        foreach $number (@_) {
            if ($number > $current_max) {
                $current_max = $number;
            }
        }
    return($current_max);
}
sub range {
    $max = max(@_);
    $min = min(@_);
    return($max - $min);
}
print range(@car_prices)."\n";
print range(@flight_prices)."\n";