man bought a new house.
The lights in the basement were connected to the switches on the 3rd floor.
The lights and switches are scrambled and you can only go downstairs once.
You can also switch on lights and switch them off as many times as you like.
Question : How can he figure out which switch belongs to which lightbulb?
Hint : Obey a the rules and you can't use anything but yourself
See the answer