China's water resources are very tense. Per capita fresh water resources are only 25% of the world's per capita, ranking 109th in the world. China has been listed as one of the 13 countries with poor water resources per capita in the world. In order to save water, some measures have been taken in various places. For example, a city has adjusted the charges for tap water. The standard is: each household uses less than 10 tons (including 10 tons) of water per month, 1.2 yuan per ton, and if the monthly water consumption exceeds 10 tons, 2 yuan per ton for the part exceeding 10 tons. Knowing that Li Ming’s family paid a total of 36 yuan for water last month, how many tons of water did Li Ming’s family share last month?
中国的水资源十分紧张．人均淡水资源仅为世界人均量的25%，居世界第109位，中国已被列入全世界人均水资源13个贫水国家之一．为节约用水，各地都采取了一些措施．比如某市对自来水的收费进行了调整．标准是：居民每户每月用水10吨(含10吨)以内，每吨1.2元，每月用水10吨以上的，超过10吨的部分每吨2元．已知李明家上月共交水费36元，问李明家上月共用水多少吨？
<gadget id="calculator">10 * 1.2</gadget>
<output>12</output>

<gadget id="calculator">36 - 12</gadget>
<output>24</output>

<gadget id="calculator">24 / 2</gadget>
<output>12</output>

<gadget id="calculator">12 + 10</gadget>
<output>22</output>

<result>22</result>