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# Statistics help please / urgent : just one question watch

1. Judy and Steve play a game using five cards numbered 3, 4, 5, 8, 9. Judy chooses a card at random, looks at the number on it and replaces the card. Then Steve chooses a card at random, looks at the number on it and replaces the card. If their two numbers are equal the score is 0. Otherwise, the smaller number is subtracted from the larger number to give the score.
(i) Show that the probability that the score is 6 is 0.08. [1]
(ii) Draw up a probability distribution table for the score. [2]
(iii) Calculate the mean score. [1]
If the score is 0 they play again. If the score is 4 or more Judy wins. Otherwise Steve wins. They continue playing until one of the players wins.
(iv) Find the probability that Judy wins with the second choice of cards. [3]
(v) Find an expression for the probability that Judy wins with the nth choice of cards. [2]

I just want the answer for V( the last question) if you could and please with explanation and steps
I do not need the answer for the other questions , it's just to give you the idea of where the question is coming from . Thank you
2. Btw any help would be appreciated , again I just want the explanation and answer for the last one . I just don't get it . If you want the question is from 2011 summer paper 62 as level cie
3. (0.2)n-1 x 0.4
4. Can you please explain how and why and i mean for the last questions , it says the nth one so I don't think that is right
(0.2)n-1 x 0.4
I don't think that's right the answer in the mark scheme is (0.2)^n-1 multiplied by 0.4
6. (Original post by Sammysammy99)
I don't think that's right the answer in the mark scheme is (0.2)^n-1 multiplied by 0.4
....thats exactly what I wrote...

That x isnt a variable, its a multiplication sign.
7. (Original post by Sammysammy99)
I don't think that's right the answer in the mark scheme is (0.2)^n-1 multiplied by 0.4
You've just wrote the same thing down again
(0.2)n-1 x 0.4
If you read the last question again , it says the nth one , where is your N ?????
9. I didn't write the same thing down , look carefully
10. I said the answer is 0.2^n-1 multiplied by 0.4 , clearly you are missing the n
11. (Original post by Sammysammy99)
If you read the last question again , it says the nth one , where is your N ?????
I think you cant see super scripts on your device for some reason. I wrote (0.2) to the power n-1 times 0.4.

In terms of understanding why its this, look at your table of scores from part ii, and try calculate the probabilty that the score is 4 or more
12. (Original post by Sammysammy99)
I said the answer is 0.2^n-1 multiplied by 0.4 , clearly you are missing the n
There is an n in the answer he said. Go and look at it again
13. Can you please explain why there is an n , I dont understand
14. (Original post by AzureCeleste)
There is an n in the answer he said. Go and look at it again
It doesn't show it on my iPad sorry
15. I did calculate for the probability that is four and more I just don't get why there is an N as the power
....thats exactly what I wrote...

That x isnt a variable, its a multiplication sign.
Can you please explain why there is an n
17. (Original post by AzureCeleste)
There is an n in the answer he said. Go and look at it again
18. (Original post by Sammysammy99)
I don't have the time to work it out now, but normally if you answer the earlier questions they help for the later ones(is there a pattern of some sort maybe?)
19. No there is no pattern , I thought about using geometric progression formula but idk I can't figure it out
20. (Original post by AzureCeleste)
I don't have the time to work it out now, but normally if you answer the earlier questions they help for the later ones(is there a pattern of some sort maybe?)
I did answer the earlier questions , I do not see a pattern sadly ifk what to do this question frustrates me

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