There are several bags of rice in the cafeteria. After eating (2/5), another 20 bags are brought in. As a result, the existing rice quantity is the original (2/3). How many bags of rice are there in the cafeteria?
食堂有大米若干包，吃掉(2/5)后，又运进20包，结果现存米量是原来的(2/3)，食堂原有大米多少包？
<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">20 / (1/15)</gadget>
<output>300</output>

<result>300</result>