Friday, August 29, 2008

Exams are getting easier right?

I made a comment on the Shuttle site on this blog entry and in it posted some of the easier questions from the GCSE paper done by the Radio 1 DJs. No-one yet seems keen to have a go so I'll post the questions exactly as presented by the exam here. No calculators allowed (not that you should need them)

  • 10 (b) (i). Factorise x2 – 13x + 30 (2 marks)
  • 10 (b) (ii). Hence, solve the equation x2 – 13x + 30 = 0 (1 mark)
  • 15. Evaluate 5–2 × 1000.5
    Write your answer in its simplest form. (3 marks)
  • 18. Leonardo is revising for his Higher tier GCSE Mathematics exam.
    He comes across this question …
    Two events A and B are independent.
    The probability of B is double the probability of A.
    The probability of both A and B occurring is 9/32
    Find the probability that event A occurs.
    Complete Leonardo’s solution.
    Let the probability of event A occurring = p
    therefore, the probability of event B occurring = 2p (3 marks)
I know there's (I should say at least) two mathmos here so their opinions on the difficulty of the questions would be interesting. Oh just for reference purposes this is the AQA Mathematics (specification A) Higher Tier for November 07. Got to love Question 18 just for the self-reference ;-)

[Update - for the entire paper in PDF format here it is]

6 comments:

Anonymous said...

Well, at the risk of ridicule.

10(b)(i) (x-10)(x-3)

10(b)(ii) x=10 or 3

15. 2/5

18. 3/8


Bit rusty but I did A level Maths 40 years ago, so I suppose I may qualify as one of your mathmos.

I consider all questions fairly simple but as there were no probability or statistics in my curriculum I had to engage brain a little for the last question.

I have not looked at the link you gave (in case the answer was there). What was the average of correct answers?

Andrew

FlipC said...

{applause} 100% correct; although I'd have arranged the equation (x-3)(x-10) :-P

The required marks for each grade were-
A* - 65%
A - 51%
B - 38%
C - 26%

For the eight Radio One DJs who took the test the results were

Carrie Davis - 28% C
Aled Hadyen Jones - 19% Fail
Dave Vitty - 14% Fail
Jenna G - 12% Fail
Greg James - 7% Fail
Dev - 1% Fail
Scott Mills - 1% Fail
Nick Grimshaw - Nil Fail.

To put it another way by just answering those 4 questions correctly (subject to marks for working out) you beat four of the above with just 9%.

I've just updated my entry with a link to the full paper if you want to have a go.

Anonymous said...

I want to know who your at least two mathmos are. I'll have you know I attained the awesome grade of U at both STEP Maths II and STEP Maths III. I'd probably get half marks at all of your questions: I could write down the answers but would never be able to remember what working-out you're supposed to show.

FTR, my brother did his GCSE maths this year and got an A. As for the self-referential probability question, Cambridge Mathematical Tripos papers are always like that. The Ia probability question is always something like "The Ia Maths examiner grades papers by throwing them down a staircase. Landing on the first step is a fail, landing on the second step gets a gamma, on the third step a beta, and on any other step an alpha. Given that the initial velocity is normally distributed according to blah blah blah, what fraction of students get alphas?" Even in computer science, I remember in my year the Ia probability question was on distributing exam results to students' pigeonholes, and given that Cambridge uses anonymous candidature, how many students can expect to receive a better mark than the one their paper got.

FlipC said...

Well I was kinda thinking of you and Invisible, guess I'll have to change that thought :-)

Heh even if you did get only half marks for that question snippet you'd still beat three of the DJs.

I do like that probability question I bet there are those who think that represents current marking methods.

Anonymous said...

Question: How do you factorise equations?

(Seriously, I have no idea how you're supposed to do this…)

FWIW, I failed epically with #15.

FlipC said...

Okay for an equation of type x^2+bx+c you split into (x+m)(x+n) where m+n=b and mn=c. So for q10b(i) we need two numbers that when added together equal -13 and when multiplied equal 30; -3 and -10 or +-2 and -+15. As it's -13 and +30 we need two identical signed values so -3 and -10.

For q15 a negative power is the inverse of the positive power so 5^-2 is the inverse of 5^2; 25 so 1/25. Fractional powers you power by the numerator and root by the denominator. So for 100^0.5 we rewrite it as 100^1/2. 100^1=100 and the square root of 100=10.

So the question can be rewritten as 1/25*10 or 10/25; in simplest form 2/5.

Now you know that, and just for fun, try 32^-2/5