Aunt Wang bought 4.5 kilograms of apples in the supermarket, handed them to the salesperson for 15 yuan, and got back 0.60 yuan. How much is an apple per kilogram?
王阿姨在超市买了4.5千克苹果，交给售货员15元钱后，找回0.60元．每千克苹果多少钱？
<gadget id="calculator">15 - 0.6</gadget>
<output>14.4</output>

<gadget id="calculator">14.4 / 4.5</gadget>
<output>3.2</output>

<result>3.2</result>