A set of "Encyclopedia of Knowledge" has 13 books, and each book is priced at 12 yuan. The school library bought 5 sets of such reading materials. How much did it cost?
一套《百科知识》有13本，每本定价12元，学校图书馆买了5套这样的读物，一共用了多少元？
<gadget id="calculator">12 * 13 * 5</gadget>
<output>780</output>

<result>780</result>