There are 120 math books, twice as many Chinese books, and 20 more story books than three times Chinese books. How many story books are there?
数学书有120本，语文书是数学书的2倍，故事书比语文书的3倍还多20本，故事书有多少本？
<gadget id="calculator">120 * 2</gadget>
<output>240</output>

<gadget id="calculator">240 * 3</gadget>
<output>720</output>

<gadget id="calculator">720 + 20</gadget>
<output>740</output>

<result>740</result>