On one side of a 120-meter-long tunnel, a total of 16 energy-saving lamps (installed at both ends) are installed from the beginning to the end. How many meters are installed on average for a lamp?
在一条长120米的隧道一侧，从头到尾共安装了16盏节能灯(两头都安装)，平均每隔多少米安装一盏灯？
<gadget id="calculator">16 - 1</gadget>
<output>15</output>

<gadget id="calculator">120 / 15</gadget>
<output>8</output>

<result>8</result>