Year 12s: what will be the first way you research your future options? >>

OCR Decision 1 - 24 May 2012

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You can't use this as an example because there was an impossible question that year which they disregarded when working out marks.

they didn't disregard it. As long as you got to the correct answer, you got full marks regardless of what fudging you tried to do afterwards [to get to their answer]

Reply 81

kofanov

Original post by icy elemental

You can't use this as an example because there was an impossible question that year which they disregarded when working out marks.

Really? That would be so cool! Do you know the question number as well as the past paper year?

Reply 82

kofanov

how many marks is question 1, 2 and 3 all together??

Reply 83

Nathdragon5

If anyone wants to take the time now to try and write out an unofficial mark scheme, that'd be very helpful, but I've got Physics tomorrow, I'll write it up after that! Don't worry about it guys, at least the general consensus is that it was hard. UMS will be low, you can pull up your average with other stuff :smile:

Good luck with all your other exams :smile:

Reply 84

tooambitious

Original post by Nathdragon5

I wonder what 100 UMS will be :P

In that case it would be 62, really hope I get it, think I dropped like 6 marks :s-smilie:

Reply 85

kofanov

does anyone knowhow many marks was question one, two and three all together?

Reply 86

Ursin

Original post by Lucozad

I atleast want a B this year. No chance for an A now, unless the grade boundaries are like this :

A - 22
B - 17
C - 12
D - 7
E - 2
U - 0

I'd probably still get an E haha

Reply 87

BobGreggary

Original post by tooambitious

In that case it would be 62, really hope I get it, think I dropped like 6 marks :s-smilie:

Really? I think you're being tooambitious

Just kidding XD, props to you if you truly think you only dropped 6 marks, that's crazy!

Reply 88

samjj8

I felt ill for the for 20 minutes. Couldn't concentrate, had to rush through everything, had to leave the room, came back felt OK afterwards, was able to do the first question at the end, didn't finish the paper, and missed loads of bits out.
The simplex was a complete joke for the amount of marks it was for.
Need to get 100% on all other modules now. :\

(edited 11 years ago)

Reply 89

Nathdragon5

Original post by tooambitious

In that case it would be 62, really hope I get it, think I dropped like 6 marks :s-smilie:

Yeah, same here, that'd be amazing to get 100 when you know you screwed up :smile:

well, best of luck to you!

Reply 90

sbchan0628

Original post by icy elemental

Question 1 involved joining up places with arcs, then using Dijkstra's algorithm to work out the shortest length from A to F. Shortest length was 49, and went AEF. A to E was 18, E to F was 31.
Last part was 1200 seconds but it asked for it in minutes so 20 minutes.

Are you sure it asked answer in minutes??

(edited 11 years ago)

100% certain

1i) Draw the diagram with 10 arcs
1ii) Complete Dijkstra's algorithm. Length = 49 Route : AEF
1ii) Time = 1200 seconds

2i) Draw a pentagon (eulerian with 5 arcs)
ii) 5 arcs, 5 vertices, semi-eulerian, one vertex with order 4 - hence join the vertices with order 1 together
iii) 5 arcs, 5 vertices, semi-eulerian (none order of 4).

3i) Connect up the subjects
3ii) The two odd nodes, D1 and M2 had to be in separate sessions. For the rest, you had to just following the arcs through.
iii) An arc is added between M1 D1 which forms a loop of 3 arcs. Explain logically why this is impossible.

4i) Simplex Question: add 'slack variables' and make equations with equals signs. The restrictions on s,t and u were that they had to be greater than or equal to 0
ii) iii)... Answer was 26.4
Slack for S was 2, hence there is 2 left other in constraint 1 (or something to that effect).

5i) Linear programming question - find equations of the lines
ii)Find optimal point
x=4/3
y=8/3
iii) Integer solution: x=2 and y=2 which gives a value of 12? for P...

5i) Can't remember. Find lower bound and upper bound etc.

6i) X=-0.2
ii) X decreases by 1 and goes back to X=0
iii) The algorithm gives the same root as in part i but with more decimal places and ridiculous fractions (what is the point in that question?)
iv) Unsure

(edited 11 years ago)

Reply 93

tooambitious

Original post by BobGreggary

Really? I think you're being tooambitious

Just kidding XD, props to you if you truly think you only dropped 6 marks, that's crazy!

I see what you did there :wink:

, to work out 100 you do A +2*(A-B), yeah I spent like 1 hour on the first 5 qs, because I expected time pressure so I rushed, then 30 mins on the last q, which I kept on misreading :facepalm: