A
light bulb is hanging in a room. Outside of the
room there are three switches, of which only one
is
connected to the bulb. At the start, all switches
are
'off' and the bulb is not lit.
You
are allowed
to
enter
the room only
once
to check the bulb
(the bulb
is not visible from the outside).How
can you
determine with which of the three
switches
the light bulb can be switched on?
