If 2 cards are selected from a standard deck of 52 cards without replacement, find these probabilities.
a. Both are of the same suit.
b. Both are kings.

Question

If 2 cards are selected from a standard deck of 52 cards without replacement, find these probabilities.
a. Both are of the same suit.
b. Both are kings.

ddcamp · Answer

a)
No matter what the first card is, it will always be in a suit. Then for the second card, there are 51 cards left and only 12 of them are the same suit as the first one.

b) 
The probability of the first card being a king is 4/52. The probability of the second being a king are 3/51 (there is one less card and one less king.
The probability of both being a king is (4/52)×(3/51)

ivettef365 · Answer

the first question is asking for the same suit, therefore it is 13/52 x 12/51

ddcamp · Answer

But it doesn't say the specific suit. If it said "both are diamonds" then it would be (13/52)×(12/51). But the first card can be anything as long as the second card is the same suit.

ivettef365 · Answer

But is says "same suit" it could be 2 diamonds, two spades, or any two of same suit

anonymous · Answer

@DDCamp so is it just 12/51?

ivettef365 · Answer

No it is 13/52 multiplied by 12/51

ddcamp · Answer

No, it's 12/51.

The first card can be anything. There is a 100% chance that when you draw a card it will be a card.
Then there is a (12/51) chance that the second card will be of the same suit.