Probability question ,Random variables and probability distribution

  • Thread starter tj00343
  • Start date
  • #1
63
0
I'm completely lost on this probability problem,

Homework Statement



A Box contains 5 indiscernible CDs.It is known that among them 2 are for children .So in order to find the first children's CD ,they are tested one after the other (successively ),Denote by X the random variable which represents the number of tests until the first children's cd is spotted

1- List all the possible values of X

2-Determine the probability distribution of X

3- Calculate the probability that at least 2 tests were performed

2. The attempt at a solution

1- x={1 2 3 4 }
2- very lost here
3- I can't solve without part 2

thank you
 
Last edited:

Answers and Replies

  • #2
vela
Staff Emeritus
Science Advisor
Homework Helper
Education Advisor
15,038
1,610
Is this a trick question? They're CDs, so you'll never spot a book. :wink:

You should be able to tell us the probability that X=1.
 
  • #3
Ray Vickson
Science Advisor
Homework Helper
Dearly Missed
10,706
1,722
Is this a trick question? They're CDs, so you'll never spot a book. :wink:

You should be able to tell us the probability that X=1.

You should also be able to tell us the probability that X = 2. After that, you should be able to do X = 3 and X = 4.

RGV
 

Related Threads on Probability question ,Random variables and probability distribution

Replies
10
Views
15K
Replies
3
Views
2K
Replies
2
Views
7K
  • Last Post
Replies
0
Views
2K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
3
Views
2K
  • Last Post
Replies
1
Views
4K
Replies
0
Views
2K
Replies
9
Views
5K
Top