Huaxia Library Building originally had 360,000 volumes of books, among which the ratio of literature and art books to science and technology books was 7:2. After buying some literature and art books, the number of literature and art books accounted for 84% of the total number of books. How many thousands of volumes are there in the Huaxia Library?
华夏图书楼原有图书36万册，其中文艺书与科技书的比是7：2．又买进一些文艺书后，文艺书的册数占图书总册数的84%．现在华夏图书楼共有多少万册？
<gadget id="calculator">7 + 2</gadget>
<output>9</output>

<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">84 / 100</gadget>
<output>21/25 = around 0.84</output>

<gadget id="calculator">1 - (21/25)</gadget>
<output>4/25 = around 0.16</output>

<gadget id="calculator">(2/9) / (4/25)</gadget>
<output>25/18 = around 1.388889</output>

<gadget id="calculator">36 * (25/18)</gadget>
<output>50</output>

<result>50</result>