The library bought 240 science and technology books, 20 more than the literature and art books (2/5), how many literature and art books were bought?
图书室买来240本科技书，比买来的文艺书的(2/5)多20本，买来文艺书多少本？
<gadget id="calculator">240 - 20</gadget>
<output>220</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">220 / (2/5)</gadget>
<output>550</output>

<result>550</result>