Uncle Wang put 15 white rabbits and 12 gray rabbits in 3 cages. On average, how many rabbits are in each cage?
王大爷把15只白兔和12只灰兔装在3个笼子里，平均每个笼子装几只兔？
<gadget id="calculator">15 + 12</gadget>
<output>27</output>

<gadget id="calculator">27 / 3</gadget>
<output>9</output>

<result>9</result>