Xiaoyan is going to read some extracurricular books during the holidays. There are 2 different science and technology books, 5 different world famous books, and 3 different biographies. Xiaoyan wants to read one of each of the three types of books. different options.
假期小严准备读一些课外书，有2本不同的科技书、5本不同的世界名著、3本不同的人物传记，小严要从三类书中各选一本阅读，则小严一共有多少种不同的选法．
<gadget id="calculator">2 * 5 * 3</gadget>
<output>30</output>

<result>30</result>