Question 8
There are 3 air conditioning units in John's house and one new air conditioning unit was installed over the summer. However, due to power limitations of his electric meter, if all 4 air conditioners are turned on at the same time, the fuse will overload, so only 3 of them can be turned on at the same time. So, in a 24 hour period over the summer, if 3 air-conditioning units are always turned on, then at least how long is the most used air conditioning unit turned on? Give your answer in hours.