Math
posted by Sam .
Suppose that you select 2 cards without replacement from an ordinary deck of playing cards.
a) If the first card that you select is a heart, what is the probability that the second card that you select is
an heart?
b) If the first card that you select is an ace, what is the probability that the second card that you
select is a spade?

a. First card = 13/52, second card = (131)/(521)
b. If the first card is hearts, clubs or diamonds, spade = 13/(521). If the first card is the ace of spades, spades = (131)/(521) 
Carol has one set of 12 trading cards and another set of 15 trading cards. She sorts the cards into 3 equal groups. How many cards are in each group?