my %value = (
    A => 1.5,
    B => 2.5,
    C => 3.5,
);

my %factor = (
    A => 50/100,
    B => 55/100,
    C => 60/100,
);

##</code><code>##

my @letters = split //, $expanded_string;
my $result = 0;
for my $letter (@letters) {
    $result = $result + $value{ $letter } * $factor{ $letter };
};

print $result;

##</code><code>##

$result = 1.5 * (50/100) * 2 + 2.5 * (55/100) * 2 + 3.5 * (60/100) * 2