Xiao Wang and his 7 colleagues installed a total of 400 air conditioners in 5 days. How many units are installed per person per day on average?
小王和他的7个同事5天共安装了400台空调，平均每人每天安装多少台？
<gadget id="calculator">1 + 7</gadget>
<output>8</output>

<gadget id="calculator">400 / 5 / 8</gadget>
<output>10</output>

<result>10</result>