Fun Riddles

Question: There are 3 switches downstairs, each corresponding to one of the light bulbs upstairs. How can you figure out which light switch goes to which light bulb by only making 1 trip upstairs?

Question: How can you make the following true by adding a single line: .9 = 1.

Note: ≠ is not the answer.

Question: Poke your fingers in my eyes and I will open wide my jaws. Linen cloth, quills, or paper, my greedy lust devours them all.

What am I?

Question: You have a flashlight that takes 2 working batteries. You have 8 batteries but only 4 of them work.

What is the fewest number of pairs you need to test to guarantee you can get the flashlight on?

Question: What is at the begining of the end, the start of eternity, at the end of time and space, was in the middle of yesterday but is nowhere in tomorrow?