There are 3, 5 and 4 story books on the upper, middle and lower shelves respectively. If you want to take a book from each shelf, how many different ways are there?
书架的上、中、下层各有3本、5本、4本故事书．若要从每层书架上任取一个本书，共有多少种不同的取法．
<gadget id="calculator">3 * 5 * 4</gadget>
<output>60</output>

<result>60</result>