Dad bought 9.5 kilograms of apples, handed them to the salesperson for 30 yuan, and got back 7.20 yuan. How much is an apple per kilogram?
爸爸买了9.5千克的苹果，交给售货员30元，找回7.20元．每千克的苹果是多少元？
<gadget id="calculator">30 - 7.2</gadget>
<output>22.8</output>

<gadget id="calculator">22.8 / 9.5</gadget>
<output>2.4</output>

<result>2.4</result>