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# I need some help in S1

Maths and statistics discussion, revision, exam and homework help.

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1. I need some help in S1
Guys, there is a question that i can't solve in S1 past paper january 2011 question 7, its really complicated. And what does the tree diagram refer to ? Event A or B, and how do i find the missing values. If anyone could help me then please do cuz i realllly need some help here !!!
2. Re: I need some help in S1
Ill be happy to help, i was a pro in statistics, send me the link to the question right away !
3. Re: I need some help in S1
Can you

• Give the question
• Or link to the paper
• Or, at least, tell us the board
4. Re: I need some help in S1
(Original post by Grim Rinazyte)
Guys, there is a question that i can't solve in S1 past paper january 2011 question 7, its really complicated. And what does the tree diagram refer to ? Event A or B, and how do i find the missing values. If anyone could help me then please do cuz i realllly need some help here !!!
There are several board that offer S1, which board paper is it?

And it will be better if you post the question or give a link to it, rather than asking us to find.
5. Re: I need some help in S1
sorry, i thought you already have it, anyways here's the link and thanks :
http://www.edexcel.com/migrationdocu...e_20110114.pdf
6. Re: I need some help in S1
7. Re: I need some help in S1
(Original post by Grim Rinazyte)
Guys, there is a question that i can't solve in S1 past paper january 2011 question 7, its really complicated. And what does the tree diagram refer to ? Event A or B, and how do i find the missing values. If anyone could help me then please do cuz i realllly need some help here !!!
The tree diagram refers to the removal of each ball and the probability that it is red or yellow

The numbers on the tree diagram are fairly obvious

TBH I am not sure why you think it is complicated

Do you understand what is happening in terms of the 2 bags and the balls?
Last edited by TenOfThem; 07-05-2012 at 21:50.
8. Re: I need some help in S1
No i mean it refers to the removal of each ball from WHICH bag and how to find the missing values for P(R,R,R) and P(R,R,Y)
9. Re: I need some help in S1
oh right, and the missing values for P(Y,Y,R) and P(Y,Y,Y)
10. Re: I need some help in S1
The first column is the first removal from P

The second column is the second removal from P

The third column is the removal from Q
11. Re: I need some help in S1
(Original post by Grim Rinazyte)
Guys, there is a question that i can't solve in S1 past paper january 2011 question 7, its really complicated. And what does the tree diagram refer to ? Event A or B, and how do i find the missing values. If anyone could help me then please do cuz i realllly need some help here !!!
Awnser the question step by step first.
P(A)
A= 2 balls drawn from bag P are of the same colour.
Which implies only two possible results
red-red, or yellow-yellow
find the probability of the two seperate possibilities and then add them up!
12. Re: I need some help in S1
but why is the answer for P(R,R,R) 2/3 ??
didnt u say it refers to the removal from bag Q and in bag Q there are 9 balls ??????
13. Re: I need some help in S1
R1 = 1/2 (there are 3/6 red balls in P)

R2 = 2/5 (there are 2/5 red balls in P)

R3 = 2/3 (there are 6/9 red balls in Q)

1/2 x 2/5 x 2/3 = 2/15

Where do you get 2/3 from?
14. Re: I need some help in S1
dude its in the mark scheme, oh wait i get it, they've actually simplified 6/9 to 2/3
15. Re: I need some help in S1
phew thanks alot guys for your help, now i understand it !! i actually thought that there were 3 removals from bag Q. this is in fact the first time i solved such a question, all the questions in the book are simple. i appreciate your help
16. Re: I need some help in S1
Ok

not sure what the issue was but pleased to help
17. Re: I need some help in S1
If you need help with stats again, I'd be happy to help (A in S1 in January)
18. Re: I need some help in S1
Good Luck mate

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Last updated: May 7, 2012
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