Jane Street–styleQuant ResearcherQuantitative ResearcherQuestion #406

You have two decks of cards: a 52-card deck (26 black, 26 red) and a 26-card deck (13 black, 13 red). You randomly draw two cards and win if both are the same color. Which deck would you prefer? What if the 26-card deck was randomly drawn from the 52-card deck? Which deck would you prefer then?

Build Your Approach

State the assumptions, try a simple case, then work toward a general solution. Check the result and explain how it changes if an assumption changes.

Try the free diagnostic with worked solutions →

Get Free Interview Prep Resources

Practice the Reasoning Behind the Answer

Bring your target roles and interview timeline to a free quant consult. Discuss your preparation priorities and how Quant Blueprint’s lessons, practice and mock interviews can help.

Book a Free Quant Consult

Your goals · your preparation · your next steps