A three-layer bookshelf holds 900 books in total. If (1/3) of the book on the second floor is moved to the first floor, and (1/4) of the book on the third floor is moved to the second floor, then the number of books on the three floors is just equal. What percentage is the number of books on the first floor of this bookshelf compared to the third floor?
一个三层书架，共放书900本．如果把第二层上书的(1/3)搬到第一层，把第三层上书的(1/4)搬到第二层，那么三层上书的本数正好相等．这个书架上原来第一层的本数是第三层的百分之几？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">900 / 3 / (3/4)</gadget>
<output>400</output>

<gadget id="calculator">900 / 3</gadget>
<output>300</output>

<gadget id="calculator">400 * (1/4)</gadget>
<output>100</output>

<gadget id="calculator">300 - 100</gadget>
<output>200</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">200 / (2/3)</gadget>
<output>300</output>

<gadget id="calculator">900 - 400 - 300</gadget>
<output>200</output>

<gadget id="calculator">200 / 400</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>