Dad bought 3 identical thermos bottles and 1 kettle for 120 yuan. If each thermos bottle is 28.5 yuan, how much is each kettle?
爸爸用120元钱买了3个同样的热水瓶和1个水壶，如果每个热水瓶28.5元，那么每个水壶多少钱？
<gadget id="calculator">28.5 * 3</gadget>
<output>85.5</output>

<gadget id="calculator">120 - 85.5</gadget>
<output>34.5</output>

<result>34.5</result>