Two men walk into a restaurant. One man orders H2O. The second man says, “I will have H2O too.” The second man dies. How come the second man dies?

Answer: H2O too = H2O2 (Hydrogen peroxide) which is poisonous and can cause death.

More Difficult Riddles with answers

More Difficult Riddles

Two people are born at the same moment, but they don't have the same birthdays. How could this be?
Two schoolgirls were traveling from the city to a dacha (summer cottage) on an electric train. "I notice," one of the girls said "that the dacha trains coming in the opposite direction pass us every 5 minutes. What do you think-how many dacha trains arrive in the city in an hour, given equal speeds in both directions?" "Twelve, of course," the other girl answered, "because 60 divided by 5 equals 12." The first girl did not agree. What do you think?
Used on a diamond and left on a board. It's great for a gymnast his grip to restore. What is it?
Useful tool for who in darkness dwell. Within you, corrupting like a deadly spell.
Using only brackets, parentheses, and these signs +,-, X, /. How can you express 100 with 5 1's and express 100 three ways with five 5's?
Vikings use this for warmth.
Voiceless it cries, wingless flutters, toothless bites, mouthless mutters.
Voiceless it cries, Wingless flutters, Toothless bites, Mouthless mutters. What is it?
Walk on the living, they don’t even mumble, Walk on the dead, they mutter and grumble. What are they?
Walk on the living, they don't even mumble. Walk on the dead, they mutter and grumble.
Walking home one day, you take a short cut along the train tracks. The tracks cross a narrow bridge over a deep gorge. At the point you are 3/8 of the way across the bridge, you hear the train whistle somewhere behind you. You charge across the bridge, and jump off the track as the train is about to run you down. As it happens, if you had gone the other way, you would have reached safety just before being run over as well. If you can run ten miles per hour, how fast is the train moving?
We are all around, yet to us you are half blind. Sunlight makes us invisible, and difficult to find