standard_description: Understand the conditional probability of A given B as P(A and B)/P(B), and interpret independence of A and B as saying that the conditional probability of A given B is the same as the probability of A, and the conditional probability of B given A is the same as the probability of B.
problem_activity: Problem 1
There are four red envelopes, four blue envelopes, and four $1 bills, which will be placed in four of the eight envelopes.
Below is a tree diagram we can use to answer the questions that follow. Write in the probabilities described.
Suppose one $1 bill is placed in a blue envelope, and the three remaining $1 bills are placed in three red envelopes.
[IMG]
If you choose a blue envelope, what is the probability that you will get the $1?
If you choose a red envelope, what is the probability that you will get the $1?
Problem 2
Suppose the $1 bills are redistributed among the envelopes. Two $1 bills are placed in two blue envelopes, and two $1 bills are placed in two red envelops. Record the probabilities on the tree diagram.
[IMG]
If you choose a blue envelope, what is the probability that you will get the $1?
If you choose a red envelope, what is the probability that you will get the $1?


aligns: yes