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?
Create a new deck of the exactly same number of cards as are face up cards in the original deck.Take 15 number of cards in a new deck and change their face direction. For example- You create a new deck of 15 cards and out of 15, 5 faces up in a new deck. So remaining 10 faces up are in the old deck. But hey! while creating the new deck you reversed the face direction of new cards. So actually the 5 cards which were facing up are actually face down in the new deck while 10 faces up.