The school bought a batch of new books, including 120 literature and art books, 20 more than science and technology books (2/5). How many science and technology books did the school buy?
学校买来一批新书，其中文艺书有120本，比科技书的(2/5)多20本．学校买来科技书多少本？
<gadget id="calculator">120 - 20</gadget>
<output>100</output>

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

<gadget id="calculator">100 / (2/5)</gadget>
<output>250</output>

<result>250</result>