Flour is 2.14 yuan per kilogram, and rice is 2.84 yuan per kilogram. If you buy 15 kilograms of flour and 15 kilograms of rice each, and pay 100 yuan, how much should you get back? (answer in two ways)
面粉每千克2.14元，大米每千克2.84元．买面粉和大米各15千克，付出100元，应找回多少元？(用两种方法解答)
<gadget id="calculator">2.14 * 15</gadget>
<output>32.1</output>

<gadget id="calculator">2.84 * 15</gadget>
<output>42.6</output>

<gadget id="calculator">32.1 + 42.6</gadget>
<output>74.7</output>

<gadget id="calculator">100 - 74.7</gadget>
<output>25.3</output>

<result>25.3</result>