There are four households in a certain building. If the air conditioners of these four households are turned on at the same time, the fuse will be blown. Therefore, only three air conditioners can be turned on at the same time. Question: how many hours can each household be turned on on average day and night?
某幢大楼有四户人家，如果这四户人家的空调同时打开，则保险丝要烧毁，因此每次只能同时打开3台空调，问：昼夜平均每户人家最多可以开几小时？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">24 * (3/4)</gadget>
<output>18</output>

<result>18</result>