SOLUTION: Sally places 12 pieces of paper in a basket. Eight are yellow and four are red. Find the probability of the following. a. if one piece of paper is drawn and is replaced before the

Algebra ->  Probability-and-statistics -> SOLUTION: Sally places 12 pieces of paper in a basket. Eight are yellow and four are red. Find the probability of the following. a. if one piece of paper is drawn and is replaced before the      Log On


   

Question 261315: Sally places 12 pieces of paper in a basket. Eight are yellow and four are red. Find the probability of the following.
a. if one piece of paper is drawn and is replaced before the second piece of paper is drawn, what is the probability of both pieces of paper being red?
b. Refer to "a" If the first piece of paper is not replaced before the second is drawn, what is the probability that both pieces of paper are red?
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
12 pieces of paper
eight yellow
4 red.

question a:

p(first red) = 4/12
p(second red) = 4/12

p(red and red) = (4/12) * (4/12) = (16/144) = .11111111...

question b:

p(first red) = 4/12
p(second red) = 3/11

p(red and red) = (4/12) * (3/11) = 12/132 = .0909090909...