finite math
posted by ryan .
three cards are randomly drawn without replacement from a standard deck of 52 cards. What is the probability of drawing an ace on the third draw?

well, you could draw these
AAA
??A
A?A
?AA to get an ace on the third draw.
Pr(aceonthird)= sum of above
=4/52*3/51*2/50 + 48/52*47/51*4/50+4/52*48/51*3/50+ 1*4/51*3/50
= 1/(52*51*50) * [24+(57*48*4)+(12*48)+ 12]
grab your calculator. check my work