what they playing at - i had to rush through the last 20 mark question because it took bloody ages drawing the dynamic programming table and the critical path diagram.
i thought questions 1 - 3 were alright, but 4 had some tricky parts that i hadn't revised the parts on max . flow through node etc.
Everything was alright. Until I walked out of the exam and realised that I've cocked up big time
The dynamic programming tabulation was supposed to have 2 at the top, right?
(I may have worked forwards... anyone any idea how many marks dropped is that? All of them?)
Everything was alright. Until I walked out of the exam and realised that I've cocked up big time
The dynamic programming tabulation was supposed to have 2 at the top, right?
(I may have worked forwards... anyone any idea how many marks dropped is that? All of them?)
for stage coloumn, top left? i went down from 2 to 0.
i got 24 for both dynamic and critical path, with c.activites being CJL or CIL , cant remember.
It was good up until they said put your pens down, missing out all 17 marks on the last page. Is D2 a maths test or a race? I would like to know, since they seem to forget theyve just asked you to draw out the same **** a million times.
My tabulation started at 2. Cant quite remember the answer....24 I think...? UNsure.
EDIT: DOes anyone know grade boundaries usually for d2?
Thanks guys. Goodbye 11 marks (or maybe 10, got 24 as well)
I dont think they will be that harsh - especially witht he right answer. You'll get marks for the layout of tabulation and also knowing how to work out and pick out maximums.
Thanks guys. Goodbye 11 marks (or maybe 10, got 24 as well)
mate, look at some previous mark schemes. they award marks going down table. you'll lose 1 i think at most, they might not even award marks for that part, or not even notice it.
i'm just trying to remember some of my answers so we can compare 'em and i can then start some C4 revision
Hi
I thought it went well.
It was time pressured but standard questions came up.
Question 4 was tricky with the E mazximised part.
but question 1 was time consuming.
Question 2 was ok as DP was just a maximum and not minimax etc and the CPA was the same network as the DP network no dummy activities.
Question 3 was also a standard game theory question with M as -0.25.
I dont think they will be that harsh - especially witht he right answer. You'll get marks for the layout of tabulation and also knowing how to work out and pick out maximums.
I doubt it. There was a similar question on the Jan 06(?) paper. Working forwards gets M0 M0 M0, and you can't get the A1 marks without the M1, can you...?
(But hang, can you get marks for the stage/state and action columns even with it being working forwards? Haha, sorry, clutching at the straws here. xP)
And yeah, time was something of an issue. Q3, last part, did everyone get M = -0.25?
I doubt it. There was a similar question on the Jan 06(?) paper. Working forwards gets M0 M0 M0, and you can't get the A1 marks without the M1, can you...?
(But hang, can you get marks for the stage/state and action columns even with it being working forwards? Haha, sorry, clutching at the strings here. xP)
And yeah, time was something of an issue. Q3, last part, did everyone get M = -0.25?
mate, look at some previous mark schemes. they award marks going down table. you'll lose 1 i think at most, they might not even award marks for that part, or not even notice it.
i'm just trying to remember some of my answers so we can compare 'em and i can then start some C4 revision
The only similar qu. is the one in 06, where you were actually asked to draw one (think all the other years you were given inserts...? :/), where forward working lost 3 of the M marks.
The only similar qu. is the one in 06, where you were actually asked to draw one (think all the other years you were given inserts...? :/), where forward working lost 3 of the M marks.
Jan 06 Q 2 explicity asks you to work from stage 1, so I think you can work forwards. Edit: Diagram looks similar aswell. Edit 2: Actually, it doesn't; it's in reverse
1) nice bipartite, and another nice bipartite. found path and a matching.
another matching was to swap B's and C's sandwiches around i think. hungarian gave 23 total?
2) maximum i got as 24? and route (0,0)-(1,3)-(2,0)-(3,0) - might have remembeed wroung,
but i know it was 7 - 10 - 7.
critical path analysis, i originally drew it without dummys but then i thought it would mean
the last two letters were all coming out of one and thus too many were predecessors.
so i redrew it all with about 500 dummys, and got 24 but far too many boxes, a whole network
covering the page. i'll lose a few marks for the network i think. and for critical activities
i got CIJ? OR CJL, can't remember.
3) made zero sum.. , -1, 6, 4 is numbers i can remember, dominated by y, play safe were
top row for R's, and middle row for C's - can't remember dogs names, reduced and got
the expressions, plotted on graph and got p = 5/8?. then showed new table from adding 4 to
each element and showed expressions. why does M show it was maximal ??????
i then worked out M as -0.25
4) had about 5 minutes to race through this question!
cut was 23 if i remembered correctly, explained why the arcs can't be at full capacity,
i got max flow through E as 9../, can reduce E by 5., you could augment by 4.
then used max.flow min cut theoerm and found a cut of 13?
Maths exam discussion - share revision tips in preparation for GCSE, A Level and other maths exams and discuss how they went afterwards.
OCR D2 June 1st 2009
