Untitled

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <title> js first project</title>
    <script type="text/javascript" src="jquery-2.1.3.min.js"> </script>
    <script>
        var prime, a, b,c;
        $ (document).ready(function(){
            a=7;
            b=3;
            c=a*b;
            prime=$('#fx');
            setTimeout('changetext()',1200);
            setTimeout('another()',3600);
        })
        function changetext(){
            prime.text(a+'*'+b+'='+'?')};

            function another(){

                prime.text(c)

            };

     </script>
</head>
<body>
<h3 id="fx"> Hello World ! </h3>
</body>
</html>