Two cards are randomly selected, without replacement, from a standard deck of playing cards. What is the probability of first picking a five and then picking a card other than a five?
I'm having a time with determining which formula to use?



Answer :

AL2006
When the deck is fresh, it has 52 cards, and 4 of them are fives.
The probability of picking a five is ( 4 / 52 ).

Now the deck has 51 cards in it, and 48 of them are not fives.
The probability of picking a not-five is ( 48 / 51 ).

The probability of both successes in order is

( 4/52 ) x ( 48 / 51 ) = 7.24 %  (rounded)

I have no idea which formula to use.  Let me know if my answer is wrong.