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Arsey's S1 Edexcel Answers 18th Jan 2013

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Quick question guys do you think I'll lose marks for the probability distribution for B (question 6a) if I wrote the x values of 1 and 3 and 5 separately e.g X 1 1 3 3 5 5 and then the probability of each 1/6 as opposed to what's done in the model answers (joining them all together) ???
cos they way I did it isn't wrong just not well done!

i did the exact same thing lol ! not sure if we'll get any to be honest :/ :L

Reply 241

sakibahmad

I HATE the histogram question, 5.a)!! it annoys me -_-
plus 5.e) didnt make sense of how to do it, i just got 0, because i took away the probabilities, si hould get 1/4 marks for 5.e)+f). I said that its skewed so normal distribution shouldnt work.

6.f) BADLY worded, i made a mess of my tree diagram, i hope it makes sense LOL, but i think i wrote the Probablity of her winning but i didnt write like the way the model answer showed. I've never seen a question like this.

All in all, C1 C2 and S1 have surprised me, like the trickiness of certain questions in C1 and S1 but also the easiness (if thats not a word, dont bite) of C2.

Reply 242

gooner4ever

Original post by MathMad

i did the exact same thing lol ! not sure if we'll get any to be honest :/ :L

I'd be very surprised if we don't get at least 1! It was out of 2 marks...... Oh I'd be so gutted if I lost 2 marks just for that!! :frown:

Oh well let's live in hope!

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Reply 243

Padouken

Original post by newcastle123

(1+k)+(8+k)+(27+k)
-------------------------- =1
40

(36+3k) -1
------------- =0
40

36=1-3k

-12=1-k
k=1+12
k=13

Would I get any marks for this?

How did you even get through C1 with such a flawed understanding and use of algebra. I don't want to sound like a dick but you need to seriously step up; that's a year 8 understanding at the very best.

(edited 11 years ago)

Reply 244

tornzy

Hi Arsey, would you be uploading the answers to S2 by any chance?

Reply 245

wtrmln1245

Original post by Arsey

nah your method is wrong, so no method mark and no accuracy mark.

How many Marks do you believe i can get for just calculating p>133 correctly? I missed out the whole given that :frown:

thank you so much for the help

Reply 246

.raiden.

Can people stop talking about S2 in an S1 thread? Lol

Reply 247

Padouken

Original post by wtrmln1245

How many Marks do you believe i can get for just calculating p>133 correctly? I missed out the whole given that :frown:

thank you so much for the help

I would guess 2.. Seriously, sometimes these "haha - caught you out" questions are cleverly designed and you can only put your mistake down to your own carelessness or failure to think, rather than an unfair, ambiguous question. But this question was plain retarded - its like after the 127 hours, the phone transformed or something or she changes phones without telling the smart ass people behind this paper.

Reply 248

Chris-69

Paper Q4C: http://papers.xtremepapers.com/Edexcel/Advanced%20Level/Mathematics/Subject%20Sorted/S1/Solomon/Solomon%20K.pdf
Mark scheme Q4C: http://papers.xtremepapers.com/Edexcel/Advanced%20Level/Mathematics/Subject%20Sorted/S1/Solomon/Solomon%20K%20MS.pdf

Why is the working out for this question not the same as the one in the Jan 2013 paper?

Reply 249

Titus20

For 4c, the horribly worded question, I correctly worked out P(127<L<133). I realise now this was completely wrong thing to do, do you think any marks though?

Reply 250

dank-knight

Original post by Arsey

I know for absolute certainty that I am right as a) I have taught this for over 15 years and b) I have the actual mark scheme.

P(AnB) only equals P(A) x P(B) when they are independent.

You serious? Hahahah full marks then xdxdxd thanks man!!

Reply 251

Yohann

Hi Arsey....Thnks for the Marking scheme!
I had a question regarding the Venn diagram!
When drawing the Venn diagram, I wrote 0.32 in the B cirlce instead of 0.23 which also affected the P(AUBUC)^l to be wrong...so out of four how many marks will i lose? one or two?
From wht i think, i could be one as 1 mark would be for drawing the diagram correctly, 1 mark for the cirlce of A, 1 mark for the circle of B and the last mark for the circle of B and outside!

Pls give ur opinion! thnks

Reply 252

250310

Original post by MathMad

i did the exact same thing lol ! not sure if we'll get any to be honest :/ :L

I think we should get it tbh i means its the same thing so ya know, i hope we do :frown:

(

Reply 253

Yohann

Hey there...could u help me out wid this :

I had a question regarding the Venn diagram!
When drawing the Venn diagram, I wrote 0.32 in the B cirlce instead of 0.23 which also affected the P(AUBUC)^l to be wrong...so out of four how many marks will i lose? one or two?
From wht i think, i could be one as 1 mark would be for drawing the diagram correctly, 1 mark for the cirlce of A, 1 mark for the circle of B and the last mark for the circle of B and outside!

Pls give ur opinion! thnks

Reply 254

Arsey

Original post by Humzah96

Ok sorry for being annoying... I got my b value right but switched the bar m and bar t wrong to find a so my end formula was wrong.. Hence the next part being wrong because i used a wrong formula to work out the answer how many marks? Out of 5 in total

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2/5

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Reply 255

Arsey

Original post by Humzah96

And for getting the width right but the height wrong in historgram how many marks?

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1/3

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Reply 256

Arsey

Original post by rockthatlook18

Hi Arsey. I worked out the normal distribution in a slightly different way. wondering if you could spare a few minutes to see whether i approached it the correct way.
1) the question says that given its been 127 hours since she last charged the phone. that means we are given that her phone is still alive at 127 hours. we worked out the probability in a) of the phone lasting more then 127 hours so i did 1-0.0359 to get 0.9641 which is the probability that it lasted up to 127 hours.
2)then they want to know the probability of the phone lasting 6 more hours so until 133 hours long. i then found the probablility P(127<L>133) which is the probability it lasted the next 6 hours. i then divided this probability by the conditional probability which we are given that it lasted until 127 hours which is 1-0.0359. to get my answer.
thanks for the mark scheme, much appreciated.

1/4

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Reply 257

Arsey

Original post by mynameistessa

Heyyy for part 4c, i did P(L>133) = 0.0139 but then didn't do the " given that " probability part, how many marks would i get out of 4?

Please read the thread. 2 marks. NOT 3

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Reply 258

Arsey

Original post by EL77

btw for f i think i wrote 100 x 0.4038 which gives you 40 people which is what is predicted in the table, rather then just writing 40/100 = 0.4038. thats technically saying the same thing right?

Yes but only 1 mark because you haven't said norm dist isn't suitable since data is skewed.

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Reply 259

Arsey

Original post by totw

Hi arsey

Sorry if you have already answered this, but will you be doing a similar mark scheme for C3?

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