Jane Street

Interview Question

Quantitative Analyst Interview
Jane Street

You have two decks of cards. Each deck contains both red and black cards in equal proportion. One deck has 52 cards, and the other has 104 cards, both consisting of half red and half black cards. You may choose which deck to play with. Then, you draw two cards at random from your chosen deck. If both cards are red, you win a prize. Which deck should you choose to maximize your chance of winning, and why?

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