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Popular Card Interview Puzzle

Popular Card Interview Puzzle - 5 November

A pack of cards has 40 cards. You are blindfolded. Out of 40, 25 cards are facing down while 15 are facing up. You have been asked to divide this pack of cards into two decks - so that each deck contains an equal number of face up cards. Remember, you are blindfolded.

How will you do it?

For Solution : Click Here


  1. You cannot divide odd numbers

  2. Gather all the cards together into a single stack, being careful not to flip any. Rip each card in half, creating two stacks. Each will have 25 half cards face down and 15 half cards face up.

  3. If all face up cards are together and all face down are together too and both piles have been arranged as one then...

    Remove 15cards from pack and keep them separate. From the other pile pick a card, flip it and place it on the smaller pile. Divide the pile into 2 halves and do the same to the other pile. Now place half of smaller pile on one half of the other pile and repeat the same for leftover piles...
    I think the job is done...