Xiaohua bought 4.5kg of bananas, paid 25 yuan, got back 2.5 yuan, how much is a kilogram of bananas?
小华买了4.5kg的香蕉，付出25元，找回2.5元，每千克香蕉多少元？
<gadget id="calculator">25 - 2.5</gadget>
<output>22.5</output>

<gadget id="calculator">22.5 / 4.5</gadget>
<output>5</output>

<result>5</result>