Aunt Wang and Aunt Li met at the fruit shop to buy the same apple. Aunt Wang bought 9 kg and Aunt Li bought 7 kg. Aunt Li paid 16 yuan less than Aunt Wang. How much is an apple per kg?
王阿姨和李阿姨两人相约到水果店买同样的苹果，王阿姨买了9千克，李阿姨买了7千克，李阿姨比王阿姨少付了16元钱，每千克苹果多少钱？
<gadget id="calculator">9 - 7</gadget>
<output>2</output>

<gadget id="calculator">16 / 2</gadget>
<output>8</output>

<result>8</result>