Fangyuan School has 200 story books, 60% of the story books are equal to (2/7) the number of literary books, how many literary books are there?
芳园学校有故事书200本，故事书的60%与文艺书本数的(2/7)相等，文艺书有多少本？
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">(3/5) / (2/7)</gadget>
<output>21/10 = around 2.1</output>

<gadget id="calculator">200 * (21/10)</gadget>
<output>420</output>

<result>420</result>