The school library bought back 130 science and technology books and 210 literature and art books. The story books bought back were three times the sum of science and literature books. How many story books were bought back?
学校图书室买回科技书130本，文艺书210本，买回的故事书是科技书和文艺书总和的3倍，买回的故事书有多少本？
<gadget id="calculator">130 + 210</gadget>
<output>340</output>

<gadget id="calculator">340 * 3</gadget>
<output>1_020</output>

<result>1_020</result>