The school library bought back 260 science and technology books and 320 literature and art books. The number of story books bought back is three times that of science and art books combined. How many story books have been bought back?
学校图书馆买回科技书260本，文艺书320本．买回的故事书是科技书和文艺书的和的3倍，买回的故事书有多少本？
<gadget id="calculator">260 + 320</gadget>
<output>580</output>

<gadget id="calculator">580 * 3</gadget>
<output>1_740</output>

<result>1_740</result>