Question
Given a standard deck of 52 cards, what is the probability that two cards drawn at random will have the same rank? Note that first card drawn is not added back into the deck when the second card is drawn.
Answers
Damon
4/52 * 3/51
Damon
what I gave you was for a specific rank, like two queens
multiply by 13 because there are 13 ranks
multiply by 13 because there are 13 ranks
jolly rancher
the first card can be any
probability = 1
the second card can be only the same rank
probability = 3/51
1 * 3/51 = 3/51
probability = 1
the second card can be only the same rank
probability = 3/51
1 * 3/51 = 3/51
Damon
Go with jolly rancher !
jolly rancher
they're the same
just two ways to think about it!
just two ways to think about it!
Damon
Yours is much better. I got off on that both queens tack :)
Reiny
My reasoning is like this:
Number of pair for each rank = C(4,2) = 6
so all possible pairs of the same rank
= 13(6) = 78
possible pairs = C(52,2) = 1326
prob(pair of the same rank) = 78/1326 = 1/17
Number of pair for each rank = C(4,2) = 6
so all possible pairs of the same rank
= 13(6) = 78
possible pairs = C(52,2) = 1326
prob(pair of the same rank) = 78/1326 = 1/17