This is a very interesting puzzle contributed by Pallav Pandey – thanks Pallav! I have not solved it yet, and looking forward to working on it!
Magician M1, calls an audience on stage who pulls random 5 cards from the deck.
M1 gives one card back to the guy from the audience; and lays out other 4 cards face-up and side-by-side on the table.
The Magician M2 comes and looks at the 4 open cards and is able to name the 5th card.
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