Experimentando

Me emocioné un poco pero traté de utilizar todo lo descrito en las clases

<meta charset="utf-8">

<script type="text/javascript">
    alert("Kaozidd's age is ...");
    alert("?");    
    document.write("Old enough");
    document.write("<br>");
    setTimeout(() => { 
        document.write("Old enough");
        document.write("<br>");
        document.write("...hehe <br>"); 
        document.write("<img src='https://static.wikia.nocookie.net/memes-pedia/images/0/0d/Lol2.png/revision/latest?cb=20160319042341&path-prefix=es' alt='lol'/>")
    }, 2000);

    setTimeout(() => { 
        document.write("<br>");
        document.write("<br>");
        document.write("<br>");
        document.write("...just kidding, " + "it's ");
        document.write(2022-1996);
    }, 5000);

    setTimeout(() => { 
        document.write("<br>");
        document.write("<br>");
        document.write(
            "<h3>Kaozidd's, Sara's and Fanny's age average is: " + 
            ((26+29+30)/3).toFixed(2) + 
            "<br></h3>"
        );
        document.write("Sara's age is 30");
        document.write("<br>");
        document.write("Fanny's age is 29");
        document.write("<br>");
        document.write("<h3>The sum of their ages is: " + (26+29+30));
        document.write("</h3>");
        document.write("Sara was born in: " + (2022-30));
        document.write("<br>");
        document.write("Fanny was born in: " + (2022-29));
    }, 7000);

</script>