There are 5 different science books on the upper shelf and 6 different music books on the lower shelf. How many different ways are there to take a science book and a music book from the bookshelf at random?
书架上层有5种不同的科技书，下层有6种不同的音乐书，任意从书架上取一本科技书和一本音乐书，有多少种不同的取法．
<gadget id="calculator">5 * 6</gadget>
<output>30</output>

<result>30</result>