There is a pile of oranges and apples, of which oranges account for 45%. After adding 16 apples, oranges only account for 25%. How many oranges are there in this pile of fruits?
有一堆桔子和苹果，其中桔子占45%，再放16只苹果后，桔子就只占25%，这堆水果有桔子多少只．
<gadget id="calculator">25 / 100</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">(3/4) / (1/4)</gadget>
<output>3</output>

<gadget id="calculator">45 / 100</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">1 - (9/20)</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">(11/20) / (9/20)</gadget>
<output>11/9 = around 1.222222</output>

<gadget id="calculator">3 - (11/9)</gadget>
<output>16/9 = around 1.777778</output>

<gadget id="calculator">16 / (16/9)</gadget>
<output>9</output>

<result>9</result>