A card brainteaser has ignited heated discussions, leaving many scratching their heads as they try to find the correct answer. The puzzle, which was shared on Reddit, goes as follows: "You take a large pile of cards face down, flip 99 of them face up, and blindfold yourself.".
"You must now shuffle them so you cannot tell which 99 are face-up, then produce two piles with an equal number of cards face-up. No damaging nor inspecting cards at all, only flipping and sliding across the table." The puzzle then continues: "There will be exactly 99 face up to start, so at least one flip is necessary." The key to solving it is finding a solution that works for any number of face-down cards. It also mentions: "It should handle 99 through 9999 cards, etc. Empty piles are fine, they have 0 face up." One Reddit user shared: "I am proud to say that I figured out exactly zero of these without help." Another added: "Flip them all, then flip a single random one.".
As the challenge gained more attention, a variety of possible solutions were suggested. One Redditor proposed: "Separate them into one pile of 99 and another of the rest, and then flip the pile of 99." Someone else wrote: "If I am blindfolded, I would think they are all face down because you said you 'secretly' flipped 99 of them face up. I have no clue how to answer this but this is what is confusing me." After thinking it over, one user finally cracked the solution: "Think I've got it, assuming I'm informed of the number of cards you flip... Divide into a pile of 99 and a pile of the rest. Flip the pile of 99.
