Question

I have a standard 52 card deck. One by one, I draw cards from the deck and place them face up in front of you (without putting them back). At any point, you may stop me and say a color. If the next two cards I draw both have that color, you win. Otherwise, you lose. What is the optimal strategy?

Answer 1

Answer:

The optimal strategy would be to wait until the last three cards to reduce the unknown probability.

Explanation:

This is a question about probability. Each time you draw a card from the deck, probabilities change: therefore you have to observe which cards have been drawn already. That is the information you need to make a guess about the remaining cards of the deck. If you wait until the last three and you've been observing how many cards of each color were face up on the table, you can make a secure guess about which cards are left for you to pick from.