A person walks on the path at an equal speed, and it takes 16 minutes to walk from the first tree to the ninth tree. If this person walks for 30 minutes, which tree should he go to?
一个人以相等的速度在小路上散步，从第1棵树走到第9棵树用了16分钟，如果这个人走30分钟，应走到第几棵树？
<gadget id="calculator">9 - 1</gadget>
<output>8</output>

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

<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<gadget id="calculator">15 + 1</gadget>
<output>16</output>

<result>16</result>