Bulb and Switches

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?




Similar Riddles

In Greek mythology, the Sphinx sat outside of Thebes and asked this riddle of all travellers who passed by. If the traveller failed to solve the riddle, then the Sphinx killed him/her. And if the traveller answered the riddle correctly, then the Sphinx would destroy herself. The riddle:

What goes on four legs in the morning, on two legs at noon, and on three legs in the evening?

Oedipus solved the riddle, and the Sphinx destroyed herself.

Asked by Neha on 26 Jul 2024


Wednesday, Steve and Pam go to a restaurant to eat lunch. After eating lunch, they pay the bill. But Steve and Pam do not pay the bill. So…who does?

Asked by Neha on 26 Jun 2025

John is looking at Jenifer, but Jenifer is looking at Jacob. John is married, but Jacob is not.

Is a married person looking at an unmarried person ?

Asked by Neha on 08 Feb 2021


A bus driver was heading down a street in Mexico. He went right past a stop sign without stopping, he turned left where there was a "no left turn" sign, and he went the wrong way on a one-way street. Then he went on the left side of the road past a cop car. Still - he didn't break any traffic laws. Why not?

Asked by Neha on 14 May 2021

It has a long neck, A name of a bird, Feeds on cargo of ships, It's not alive,

What is it?

Asked by Neha on 17 May 2021

In the given picture, you can find two letters missing. When two particular letters are placed in the missing spots, you get an eight-letter word while reading in the anti-clockwise direction. Can you find out the missing letters and the missing word eventually?

Picture Puzzle

Asked by Neha on 23 Dec 2024


What Deficiency does the below rebus represent?

VIT_MIN

Asked by Neha on 09 Jun 2024

Alex opened 24 presents
Jonah opened 8 presents
Clara opened 1 present

Can you find out how many presents were opened by Candy?

Asked by Neha on 06 May 2024

You see a mathematical expression in the picture. Can you think of a movie that this expression refers to?

Movie in Maths

Asked by Neha on 05 Aug 2021


Imagine you are in a room with no windows or doors. How will you get out?

Asked by Neha on 25 Oct 2025

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Amazing Facts

Jigsaw puzzles

Jigsaw puzzles soared in popularity during the great depression, as they provided a cheap, long-lasting, recyclable form of entertainment.