【実践課題E】 

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
</head>
<body>

<table border="1">
<tr><th>商品A</th><th>商品B</th><th>商品C</th><th>商品D</th></tr>

<script>
var b=[300,450,520];

for(a=1;a<11;a++){ document.write("<tr><th>"+a+"</th>");

for(i=0;i<3;i++){ document.write("<td>"+a*b[i]+"円</td>"); }

document.write("</tr>");
}

</script>

</table>
</body>
</html>