In order to encourage water conservation, a water company in a city adopts the method of monthly billing and billing for water. 2.5 yuan per ton within 12 tons; 3.8 yuan per ton for the part exceeding 12 tons. Linlin's family used 18 tons of water last month. How much should I pay for the water?
某市自来水公司为鼓励节约用水，采取按月分段计费的方法收取水费．12吨以内的每吨2.5元；超过12吨的部分，每吨3.8元．琳琳家上个月的用水量是18吨，应缴水费多少钱？
<gadget id="calculator">2.5 * 12</gadget>
<output>30</output>

<gadget id="calculator">18 - 12</gadget>
<output>6</output>

<gadget id="calculator">3.8 * 6</gadget>
<output>22.8</output>

<gadget id="calculator">30 + 22.8</gadget>
<output>52.8</output>

<result>52.8</result>