There are a bunch of candies, among which toffee accounts for (9/20), and after adding 16 pieces of fruit candy, toffee only accounts for (1/4). How many candies were there in total?
有一堆糖果，其中奶糖占(9/20)，再放入16块水果糖后，奶糖就只占(1/4)．这堆糖果原来一共有多少块？
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

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

<gadget id="calculator">20 - 9</gadget>
<output>11</output>

<gadget id="calculator">11 / 9</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">9 / 20</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">16 / (16/9) / (9/20)</gadget>
<output>20</output>

<result>20</result>