Вот как я начал
<!DOCTYPE html>
<html lang="lt">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Egzamino uzdiotys nr1</title>
<style>
img{
height: 100px;
}
</style>
</head>
<body>
<script>
// [1;8]
var x = Math.round(Math.random()*7+1);
document.write('<a href="'+x+'.jpg" target="_blank">');
document.write('<img src="'+x+'mini.jpg"></a>');
var x1 = Math.round(Math.random()*7+1);
document.write('<a href="'+x1+'.jpg" target="_blank">');
document.write('<img src="'+x1+'mini.jpg"></a>');
</script>
</body>
</html>