There is a good harvest in the apple orchard. If each person picks 9 trees, 16 people can pick all the apples. Now there are only 8 people, how many trees does each person have to pick if they want to pick all the apples?
苹果园里丰收了，如果每人摘9棵树，16人可以摘完这些苹果．现在只来了8个人，要摘完所有的苹果，每人要摘几棵树？
<gadget id="calculator">16 / 8</gadget>
<output>2</output>

<gadget id="calculator">9 * 2</gadget>
<output>18</output>

<result>18</result>