The water company stipulates: "When the monthly water consumption does not exceed 10 tons, the fee is 2.5 yuan per ton, and the part that exceeds 10 tons is charged at 4 yuan per ton." According to this calculation, Li Ming's family used 13 tons of water last month, how much water should be paid? money?
自来水公司规定："每月用水不超过10吨时，按每吨2.5元收费，超过10吨的部分按每吨4元收费．"照这样计算，李明家上月用水13吨，应交水费多少钱？
<gadget id="calculator">2.5 * 10</gadget>
<output>25</output>

<gadget id="calculator">13 - 10</gadget>
<output>3</output>

<gadget id="calculator">3 * 4</gadget>
<output>12</output>

<gadget id="calculator">25 + 12</gadget>
<output>37</output>

<result>37</result>