Question:
You are randomly dealt 5 cards from a standard deck of 52 playing cards. What is the probability that you have at least 4 cards of the same suit?
My solution:
4 [ P(4 of the same suit) ] - because there are 4 different ways to get 4 of the same suit, Clubs, Hearts, Spades and Diamonds.
P(4 of the same suit) =
(13 C 4 * 39 C 1)/
(52 C 5)
13 Choose 4 because you have 13 different cards in one suit, and you must choose 4 of those, then for the remaining 39 cards you must choose 1.
4 [ P(4 of the same suit) ] = .0429
Does this seem like I answered the question properly?
you forgot the case where all 5 are of the same suit
"at least 4 of the same suit" means it could be 4 of the same suit or it could be 5 of the same suit.
which would be 4(13C5)/52C5
add that on to your answer
That seems to make sense to me. Thank you Reiny
Your solution seems correct for calculating the probability of getting exactly 4 cards of the same suit. However, the question asks for the probability of having at least 4 cards of the same suit, so you also need to consider the possibility of getting all 5 cards of the same suit.
To properly answer the question, you would need to calculate the probability of getting exactly 4 cards of the same suit, the probability of getting all 5 cards of the same suit, and then add them together.