Assume that there are 5 different issues of sports illustrated, 6 different issues of newsweek, and 3 different issues of time, including the december 1st issue, on the rack. you choose 4 of them at random. (1) what is the probability that you choose 1 issue of sports illustrated and 3 issues of newsweek? (2) what is the probability that you choose at least 2 of the newsweek magazines?

a. P(1 Sports illustrated and 3 Newsweek) =  

b. P(at least 2 Newsweek) =

We follow these steps to arrive at the

The total number of magazines is

Of these we need to choose 4 books randomly. Since order doesn’t matter here, we use combinations.

There are ways to choose 4 books.  

1. 1.We need to choose 1 Sports illustrated and 3 newsweeks.

We can choose 1 Sports illustrated from 5 in ways.

We can choose 3 issues of Newsweek in ways.  

So,

2. P(at least 2 Newsweek)

Here we divide the number of books into two categories. One is the Newsweek Magazines (6), the other group consists of all other books (8).

Now, if we have to find P(no newsweek), we first need to find the number of ways we can select 4 books from the group that does NOT contain Newsweek magazines.

We can calculate that by:

So,

We can compute P(1 Newsweek) as follows:

We can choose 1 Newsweek in

We can choose 3 other books in

Since

,

d,