You can buy 2.5 kilograms of apples with 27.2 yuan, and you can buy 4 kilograms of oranges with the same money, and there is 0.4 yuan left, so how much more expensive per kilogram of apples than per kilogram of oranges?
用27.2元钱可以买2.5千克苹果，用同样的钱可以买4千克橘子，还剩0.4元，那么每千克苹果比每千克橘子贵多少元？
<gadget id="calculator">27.2 / 2.5</gadget>
<output>10.88</output>

<gadget id="calculator">27.2 - 0.4</gadget>
<output>26.8</output>

<gadget id="calculator">26.8 / 4</gadget>
<output>6.7</output>

<gadget id="calculator">10.88 - 6.7</gadget>
<output>4.18</output>

<result>4.18</result>