SOLUTION: A collection of 13 greeting cards consists of 8 birthday cards and 5 thank-you cards. 7 of the cards are randomly selected for purchase. What is the probability that the 7 purch

Algebra ->  Probability-and-statistics -> SOLUTION: A collection of 13 greeting cards consists of 8 birthday cards and 5 thank-you cards. 7 of the cards are randomly selected for purchase. What is the probability that the 7 purch      Log On


   

Question 842528: A collection of 13 greeting cards consists of 8 birthday cards and 5 thank-you cards.
7 of the cards are randomly selected for purchase.
What is the probability that the 7 purchased cards consist of 4 birthday cards and 3 thank-you cards?

Found 2 solutions by ewatrrr, hamsanash1981@gmail.com:
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

P(4B and 3TY) = %288C4%29%285C3%29%2F%2813C7%29

Answer by hamsanash1981@gmail.com(151) About Me  (Show Source):
You can put this solution on YOUR website!
Given that a collection has 13 cards and no of ways selecting 7 cards is 13C7.
i.e., 858
no of ways selecting 4 birthday cards from 8 is 8C4 = 70
no of ways selecting 3 thank you cards from 5 is 5C3 = 10
Probability of selecting 4 birth day card and 3 thank you card is = 70*10/858