I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?
If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?
I have a hole in my back and legs I lack. I live where I can’t breathe and I eat without teeth. What am I?
How can you write nineteen in a manner that if we take out one, it becomes twenty?
Twenty frogs are sitting on a log floating on the surface of a river. Two of them decide to jump off into the water. How many frogs are there on the log at this moment?
A wooden log balances equally on the scales when weighed with three-quarters of a pound and three-quarters of a wooden log. Can you calculate the weight of the entire wooden log?
I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?
I am under you when I am whole. I shift above you if you remove the first letter. I come all around you if you remove the second as well. Can you tell me who I am?
If eleven plus two equals one, what does nine plus five equal?
I am the fastest animal but cannot climb the tree. What am I?
Can you write down eight eights so that they add up to one thousand?
There is a cryptic organization called Cicada 3301 that posts challenging puzzles online, possibly to recruit codebreakers and linguists.