OCR Prob and Statistics 1 June 2004 Mark Scheme?

Hi has anyone got the mark scheme for June 2004 S1?

Needed urgently!

Cheers

G

Hiya, got the mark scheme for the first 6 questions of the June 2004 OCR S2 paper...I think it's the right one...not quite sure how to add attachments though, so I could be a while...I'll give you the answers to Q7 as well in a bit, tho I don't have the breakdown of how to mark that question...hope that helps!

Reply 2

Dee27

Hmm.....attachments not really working.....well question 7 answers are:

7) i) A-B-A = 2/3 x 3/4 = ½
A-C-A = 1/3 x 4/5 = 4/15

Therefore P(returns after choosing 2 paths)=1/2 + 4/15 = 23/30

ii) ABCA = 2/15
ACBA = 1/20

Therefore P(returns to A after choosing 3 paths)=2/15 + 1/20 = 11/60

iii) ABCAB = 4/45
ACBAB = 1/30
ACBCB = 1/300
ACACB = 4/225
ABABC = 1/30

Total probability of being at B after 4 choices = 53/300

Hope this helps a bit & makes some kind of sense...do ask, if it doesn't, and if the attaching still doesn't work, I can give you any specific answers to questions, if you want...very sorry about my lack of computing skills! And good luck for tomorrow, assuming you're retaking the S1 tomorrow? :smile: