In order to encourage residents to save water, the water company stipulates that each household will be charged 1.36 yuan per ton for water consumption within 15 tons (including 15 tons) per month, and 3.5 yuan per ton for the excess tonnage of more than 15 tons. Aunt Wang’s family used 19 tons of water in April. Please do the math for her. How much should her family pay for water this month?
为鼓励居民节约用水，自来水公司规定：每户每月用水15吨以内(含15吨)按每吨1.36元收费，超过15吨的，超出的吨数按每吨3.5元收费．王阿姨家四月份用水19吨，请你帮她算一算，这个月她家应交水费多少元？
<gadget id="calculator">15 * 1.36</gadget>
<output>20.4</output>

<gadget id="calculator">19 - 15</gadget>
<output>4</output>

<gadget id="calculator">4 * 3.5</gadget>
<output>14</output>

<gadget id="calculator">20.4 + 14</gadget>
<output>34.4</output>

<result>34.4</result>