Three light bulbs in the basement.

This is an old puzzler. But a goodie. Let's see who remembers it.

There are three light switches up in the attic of an old house... They control three light bulbs down in the basement. The problem is that you don't know which switch is connected to which bulb. You can make one trip down to the basement to figure this out.

How are you going to do it?

No. There is absolutely no way you can see which ones are on or off from the attic.

Hit switch one - leave it on for awhile - turn it off.
Hit switch two.

Switch one goes to the one that is off but warm.
Switch two goes to the one that is on.
And switch three goes to the one that is off and not warm.

assume bulbs A, B, C

A = on
B = off + warm
C = off + cold

C suggesting been off for a very long time
B suggesting has just been turned off
A suggesting been on

you would start with all the switches off. i don't know how long it takes a bulb to cool off; say 4 minutes. say after 10 minutes(by this time all the bulbs in the bment are as cold as an ice cube) turn on two switches(A or B) and immediately turn off one of the two switches you have just turned on(A); still leaving one switch off(C)

match your investigations;