jquery – get a value in mix radio button

Would you like to check what wrong in my code, I have 2 group radio button when I click the radio button variable r not have a value :

<script>
$(document).ready(function() {
    var s = 0;
    var l = 0;
    var r = 0;

    $('input[type=radio][name="saverity"]').change(function() {
        s = $(this).val();
        console.log(s);
    });

    $('input[type=radio][name="likehood"]').change(function() {
        l = $(this).val();
        console.log(l);
    });

    r = s * l;
    console.log(r);

});

Thank you very much.