Teacher Gan Qiangsheng bought 6 kilograms of bananas for 14.4 yuan, and teacher Ailey bought 9 kilograms of the same bananas for 23.4 yuan. Who buys bananas more expensive? How much is it per kilogram?
干强胜老师买了6千克的香蕉用去14.4元，艾利老师买了9千克同样的香蕉用去23.4元．谁买的香蕉贵了？每千克贵多少元？
<gadget id="calculator">23.4 / 9</gadget>
<output>2.6</output>

<gadget id="calculator">14.4 / 6</gadget>
<output>2.4</output>

<gadget id="calculator">2.6 - 2.4</gadget>
<output>0.2</output>

<result>0.2</result>