In order to encourage citizens to save water, a certain city implements a charging standard based on water consumption: each household uses less than 10 tons (including 10 tons), and charges 3.5 yuan per ton; each household uses less than 15 tons (including 15 tons) ), the excess is charged at 5 yuan per ton; each household uses more than 15 tons of water, and the excess is charged at 8 yuan per ton. Aunt Li’s house used 17.5 tons of water in May. How much should I pay for the water?
某城市为鼓励市民节约用水，实行根据用水量分段收费的收费标准：每户居民用水少于10吨(包括10吨)，每吨收费3.5元；每户居民用水15吨以下(包括15吨)，超出部分每吨收费5元；每户居民用水15吨以上，超出部分每吨收费8元．李阿姨家五月份用水17.5吨，应交水费多少元？
<gadget id="calculator">10 * 3.5</gadget>
<output>35</output>

<gadget id="calculator">15 - 10</gadget>
<output>5</output>

<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<gadget id="calculator">17.5 - 15</gadget>
<output>2.5</output>

<gadget id="calculator">2.5 * 8</gadget>
<output>20</output>

<gadget id="calculator">35 + 25 + 20</gadget>
<output>80</output>

<result>80</result>