Having watched the explanation here. Had more than attempt at my 'O' Level maths which explains my failure to grasp. Then again it was a very long time ago.
http://www.bbc.co.uk/news/magazine-33023123
Having now seen the problem I really don't know what all the fuss was about. (I solved it in seconds before watching the video). It's not a tricky problem for the able candidate, which is really the whole point of the problem.
I'll lay money that a number of students gave -9 as a possible answer to the second part. Back in my day…
And if you're interested in recreational maths at a slightly lower level than say Martin Gardner, Rob Eastway's books are always a fun read.
At last...a modern exam question I can get right!
The issue for students was that it was a rather unusual problem - combining both algebra and probability. Students are taught to pass exams by practicing past exam papers not to think (even slightly) outside the box.
If that type of question hadn't been seen before they are lost. Back in the day we were taught the subject in greater depth and were better prepared for this sort of thing - probably the first exam paper we saw was ours.
'Twas pretty easy - despite the fact that I failed a maths degree some 29 years ago and haven't really done anything since.
It seemed quite similar to the sort of thing on my maths "O" level to be honest.
Cheers,
MarkC
Oh I agree in general, but the word from the exam board was that this was a question designed to separate the top few percent, which I think it does quite well. The very top grade should be able to deal with the unexpected, especially if it's just the application of fundamental knowledge, which this was.Originally Posted by Kingstepper
Continuing on the maths theme, I'm doing a second masters as a bit of a vanity project and to correct a past mistake (I don't have a bachelor's only an MEng) and have an exam on the calculus of variations this Tuesday. If all goes well that will complete my post graduate diploma in mathematics and I'll be two thirds of the way through my MSc. Thankfully no probability or sadistics [sic] should appear on the paper.
Maybe if the kids comparing about this question had spent more time revising and less time posting pictures of gurning celebrities on social media (my face when...), they wouldn't have had so much difficulty with this straightforward question.
The question was asked in a way that was unusual to the students. In a high pressure environment, some students will panic when faced with something they don't immediately recognise.
The question did not need to be asked in 2 parts. I wonder how the students would have approached the question if it was simply asked, How many sweets were in the bag?
^
Having spent many years looking at this exam paper or that it has occurred to me often that the language used to ask the question has been appreciably more difficult than the answer required.
The language is a problem?
The question give all the necessary information in short uncomplicated sentences...isn't that good?
It's not a trick question.
It tells the student that it's a probability problem by giving them the result of the probability calculation.
Part (a) tells them the equation to expect when trying to find the probability...and they already have the actual result.
The student can get marks for doing part (b) without doing or understanding part (a).
Surely that's not too difficult or awkward to understand and attempt?
I teach maths. The children lack confidence. There's just something about society today that seems to hold them back from "having a go".
Their world is reactive. Press a button on facebook, now my status is "happy" (smiley face). There isn't the "I wonder what will happen if I do this" mentality.
Part (a) tells them nothing of the sort. It simply asks them to show n^2-n-90=0. The student has to recognise what is being asked of them right from the start - to recognise that the equation shown is the simplified form of the equation to calculate the probability of drawing out 2 orange sweets.
I agree that the question was ridiculously simple.
Therefore there must be some other factor at work.
Occam's razor: I'm given to think that the students simply hadn't encountered a probability question asked in this way before.
I wonder how many of those students who had difficulty with this question, when shown the attached BBC video, would see just how simple the question really was, and may feel a little bit tricked.
I beg to differ:
I think we can agree that the question requires a little thought and understanding, rather than being amenable to solution by rote.
Last edited by PickleB; 7th June 2015 at 19:58. Reason: add last sentence
As an earlier poster has pointed out, the question was designed to identify the top few per cent (I missed this on my first read of the thread). If this was the exam boards intention, then mission accomplished.
Agreed.
No, it's not a trick question and these are GCSE candidates. 16+. But I have seen many questions phrased in a much more adult way than the level of the question itself. So, are you testing English, or Maths, and punishing if your English is not that good (second language, for instance)? No, it's too long ago now for me to provide an example.
I too cannot give any examples from the era when I took O & A Levels, but I well remember questions that were written as whole paragraphs and needed to be mentally deconstructed before I could properly understand them. Maybe it's just me, but I think that it is easier to link the individual phrases in the test question to discover the logic by which it may be solved.
It is unnecessarily wordy. She draws 2 orange sweets. Why do we need to know she eats them?
To make it absolutely unambiguous that they're not put back in the bag. If the sweets are put back in the bag then it's an entirely different problem.
Realize that would be a different problem but assumed they stayed out (don't think this is usually spelled out with balls or whatever).
A fair exam question has to be unambiguous, for both the sake of the students and the markers.
This is really an applications question and it models a real world situation quite nicely. This is what 99% of people will use their maths for, real world applications.
Somebody has a bag of mixed sweets and eats two of them. Show that the probability that they eat two of a given colour is as given. Nothing is left to guesswork, nothing is beyond the expected level of ability for GCSE, no extraneous information is given to lead the student astray, but the student does have to apply their knowledge to an unexpected situation. The student also has to realise that -9 sweets is not a valid answer for "How many sweets are in the bag?" It's a really good question.
Fair enough (although the markers have a very rigid mark scheme).
I've posted a puzzle I saw recently for anyone interested http://forum.tz-uk.com/showthread.ph...72#post3546872
And this can only happen because the question is not open to interpretation. It it was then students quite rightly could and should complain.
I've had a crack at your question too, although it's more of a psychology rather than maths question. ;-)
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