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Maths exam on the news!

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Original post by Stevo F
I haven't seen an unofficial markscheme but if you factorise n^2 -n - 90=0
you get (n-10)(n+9)=0
N=10 or -9


Oh my bad e.e
Original post by Stevo F


Nope, you would get (n-10)(n+9)=0

Gets n=10 or -9

Seeing as n must be positive n=10

Pretty simple question tbh don't get why people are so upset over it, takes a minute tops to figure out how to do it, the whole point if these exams is to test your knowledge of the topics, I'd you can't do the question when they change the format slightly then you haven't understood the topic, you've just learnt a method without understanding it.
Suck it up sometimes there are hard questions on exams, that's kind of the point of them
Original post by Stevo F


They only asked for one answer, 10 was the only plausible answer
Original post by Stevo F
I haven't seen an unofficial markscheme but if you factorise n^2 -n - 90=0
you get (n-10)(n+9)=0
N=10 or -9
Sorry for previous typo, this is the answer


Yes, but I'm sure the question was asking about sweets, and you cannot get minus sweets. So I thought the answer was only 10.
Original post by leinad2012
Nope, you would get (n-10)(n+9)=0

Gets n=10 or -9

Seeing as n must be positive n=10

Pretty simple question tbh don't get why people are so upset over it, takes a minute tops to figure out how to do it, the whole point if these exams is to test your knowledge of the topics, I'd you can't do the question when they change the format slightly then you haven't understood the topic, you've just learnt a method without understanding it.


that was just the second part of the question. The first part asked you to show it
Original post by Stevo F
I haven't seen an unofficial markscheme but if you factorise n^2 -n - 90=0
you get (n-10)(n+9)=0
N=10 or -9
Sorry for previous typo, this is the answer


N would equal 10 because I'm assuming that it's in relation to the sweets? You can't have n as a negative integer because we're talking sweets and probabilities?

there are 10 sweets. so 6/10*5/9 = 30/90 aka 1/3
Therefore n must equal 10. Bit like the start of an S1 paper in all honesty.
Original post by Fatemah99
that was just the second part of the question. The first part asked you to show it


The first part is just as simple, just rearrange;

6/n x 5/(n-1) =1/3

Again if you fully understand probabilities without replacement this question should be no problem at all
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1998111
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What was wrong with the Maths paper?
I did my GCSE Maths last year so I didn't sit this year...Feeling glad that I did it a year early now.


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Original post by leinad2012
Nope, you would get (n-10)(n+9)=0

Gets n=10 or -9

Seeing as n must be positive n=10

Pretty simple question tbh don't get why people are so upset over it, takes a minute tops to figure out how to do it, the whole point if these exams is to test your knowledge of the topics, I'd you can't do the question when they change the format slightly then you haven't understood the topic, you've just learnt a method without understanding it.


Yes, I agree it was a question that you needed to understand the concept of it (including using 'n' to replace a number), to be honest I didn't get the right answer but looking back at it was not particularly hard.
Original post by Calzyhill
Yes, but I'm sure the question was asking about sweets, and you cannot get minus sweets. So I thought the answer was only 10.


Original post by jam277
N would equal 10 because I'm assuming that it's in relation to the sweets? You can't have n as a negative integer because we're talking sweets and probabilities?

there are 10 sweets. so 6/10*5/9 = 30/90 aka 1/3
Therefore n must equal 10. Bit like the start of an S1 paper in all honesty.

They didn't ask you to find a number of sweets, they asked you to solve that equation, so the answer can be positive or negative.

P.S I'm only going on the question I've seem posted on this forum, if the question I've seen is wrong then apologies
Original post by Stevo F
They didn't ask you to find a number of sweets, they asked you to solve that equation, so the answer can be positive or negative.

P.S I'm only going on the question I've seem posted on this forum, if the question I've seen is wrong then apologies


Yes but the pre requisite is that n is the number if sweets, that's the scenario, so you know n must be a positive integer leaving only n=10
Original post by Fatemah99
that was just the second part of the question. The first part asked you to show it

Yes but it says the probability of taking two orange sweets was 1/3 in the question. You cannot get that probability if you substitute -9 in the equation.

Anyway I'm assuming you have to decipher the amount of sweets from the question and not just substitute? You can do that quite easily.

you will get n^2 -n simply because you have n sweets, then you take away one, so you have n(n-1) for the start of your equation. The second bit you have -90 because you have 6 orange sweets and then 5 orange sweets, so to find out the total you need to times 6 by 5 and times it by three(due to the probability of two orange sweets being 1/3) and you end up with your answer. I don't know how complex a GCSE exam is but that's another way to do it.
Original post by jam277
Yes but it says the probability of taking two orange sweets was 1/3 in the question. You cannot get that probability if you substitute -9 in the equation.

Anyway I'm assuming you have to decipher the amount of sweets from the question and not just substitute? You can do that quite easily.

you will get n^2 -n simply because you have n sweets, then you take away one, so you have n(n-1) for the start of your equation. The second bit you have -90 because you have 6 orange sweets and then 5 orange sweets, so to find out the total you need to times 6 by 5 and times it by three(due to the probability of two orange sweets being 1/3) and you end up with your answer. I don't know how complex a GCSE exam is but that's another way to do it.

You don't need to get that probability if they give you an equation and tell you to solve it, this part of the question is badly worded and I imagine a lot of people will put both answers..
Original post by Calzyhill
Yes, I agree it was a question that you needed to understand the concept of it (including using 'n' to replace a number), to be honest I didn't get the right answer but looking back at it was not particularly hard.


Obviously having done a levels it's tough for me to put myself in the position of someone taking a gcse paper, was the question tough for people of that ability? Yes, it's meant to test and distinguish the a from a* students. If only 5% of people got it right they'll just lower the mark scheme anyway i really don't get what the fuss is about (probably that most of the people complaining have never been stretched in maths and are now having their ability questioned)
(edited 8 years ago)
Original post by Stevo F
You don't need to get that probability if they give you an equation and tell you to solve it, this part of the question is badly worded and I imagine a lot of people will put both answers..


Ok but the basic part of probability is that it cannot be negative and the integers cannot be negative. How do you get negative 9 sweets?
Original post by jam277
Ok but the basic part of probability is that it cannot be negative and the integers cannot be negative. How do you get negative 9 sweets?

But did they ask you to solve the equation or find a number of sweets? Genuinely asking now because I haven't seen the paper and I'm basing my argument on what other people here have posted.
Also if what someone else wrote is true, they only asked for one answer, I would have only given the positive answer, but if not I would have written both
Original post by Stevo F
You don't need to get that probability if they give you an equation and tell you to solve it, this part of the question is badly worded and I imagine a lot of people will put both answers..


With all due respect (not much) you need to stop blaming the exam board for your own shortcomings. If you didn't realise that you can't have a negative total number of sweets then that's your own fault tbh, there's nothing stopping you writing a little bit to the side saying "if just solving the question then n=10 or -9, if with respect to the number of sweets then n=10 as n>0"
Original post by Stevo F
But did they ask you to solve the equation or find a number of sweets? Genuinely asking now because I haven't seen the paper and I'm basing my argument on what other people here have posted.
Also if what someone else wrote is true, they only asked for one answer, I would have only given the positive answer, but if not I would have written both


It's tough to tell without seeing it, I'd assume it's ac follow on question so n=10 would be intuitive
Original post by leinad2012
With all due respect (not much) you need to stop blaming the exam board for your own shortcomings. If you didn't realise that you can't have a negative total number of sweets then that's your own fault tbh, there's nothing stopping you writing a little bit to the side saying "if just solving the question then n=10 or -9, if with respect to the number of sweets then n=10 as n>0"

:rofl:
I didn't do the exam which is why I've been asking how the question was actually worded.
You're talking about me blaming an exam board? What about all the butthurt people signing a petition? :lol:

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