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Arsey's D1 Edexcel Summer 2013 Model Solutions BOTH PAPERS

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when you say improved matching do u mean to show in the graph? cause in the solution u put the improved mathcing in the diagram? how many marks would u lose for that thanks sir

Sir the question on 2x<3y i said the number of 2 seater cars must be at least 3/2 more as the number of 4 seater cars

it was at most 3/2 more, not at least

Reply 101

wndms

Original post by lebron_23

Does anyone know how many marks I'll lose for plotting everything right for the LP question, but marking the region R incorrectly.

Obviously, I then used vertex testing on the wrong points.. I don't even know if D1 has a such thing as error carried forward.

Also, I'm almost certain I got a U in this exam (due to circumstances and me not feeling well). Do you think universities will see this as a one off freaks result considering I have 5 A's in my other modules?

I could really kill myself right now..

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That's exactly how I feel about M1 I sat on Monday :frown:

But don't worry. You need 480/600 UmS to get an A. If you get over 90% for C3 C4 you can get an A*

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Reply 102

Smko

Original post by Gillerz

No it would be 0.66667 not 1.5

aw dam

thought it was x<3/2 Y :P

Reply 103

username964430

Original post by m4ths/maths247

(1) I doubt it as dotted lines are usually the accepted method (unless Edexcel want to be picky)

(2) That would be ok but a lot of work for 2 marks.

Phew, I was in such a rush for this exam I couldn't think clearly, the exams officer sent me outside for saying to myself 'I need to get out my stuff' and let me back in 15 minutes after the exam had already started without any extra time :frown:

But hopefully I've still made an A.

Reply 104

Smko

Original post by m4ths/maths247

(1) I doubt it as dotted lines are usually the accepted method (unless Edexcel want to be picky)

(2) That would be ok but a lot of work for 2 marks.

the 2x<3y question i said there must be at most 1.5 times as many 2seaters than 4 seaters is this right?

Reply 105

dav22

for the last question, i think it was 7G, I put 5 is the better lower bound better it takes into account the ordering events must take place in aswell as the time taken, whereas 4 just takes into account the time; would this be okay? Other than that everything else looked good I think (hopefully haha) :awesome:

Reply 106

wndms

For the constraint explanation question I wrote "every two 2 seater boats should be at most three times the 4seater boat..." is this wrong?

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(edited 10 years ago)

Reply 107

niki135

Ahh I ran out of time SO BADLY. I'm so scared I won't get my A in maths now :frown:

I need to smash my other units or that's my Uni dream over..

Arsey (or anyone else) please answer these quick questions!!!:
- for the linear programming I didn't have enough time so I only drew one of the constraints... How many marks will I get? If any..
- for the Gantt chart I didn't use the ruler for some, I had no time left, but they were straight-ish lines... Will that be okay?
- I drew a line on the chart and just wrote 5 (not 5 workers, just 5 haha), for the number of workers! I didn't have time to write anything else. Will that even be a mark?

Please answer them! I hope it's a high C and nothing lower for me :frown:

Reply 108

Caribbeantwist

Niki153: not answering your questions but I just majorly goofed up s1 and I feel exactly the same way as you!!

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Reply 109

Gillerz

Original post by Smko

aw dam

thought it was x<3/2 Y :P

Nah, sorry I think you were right, I though they were the other way around.

Reply 110

Harryg_95

Original post by Arsey

Fairly reasonable paper I thought

1. Matchings - pretty simple, although not breaking down the 2 required paths into separate part of the question, could cause problems.

2. Quick sort and Bin packing - very easy, I thought it was odd how the first-fit decreasing didn't reduce the number of bins though

3. Prim's and Kruskal's - very easy

4. Dikky - harder than normal due to the sneaky part of the route. Quite easy to mank up b) too.

5. Postie - standard. A common error on c) will be to repeat DE.

6. LP - not easy but it never is. Part b) will be a bloodbath.

alt to part b)

no more than 1.5 times as many small as large

for every 3 small you need at least 2 big

7. CPA - Fairly standard but the backward scans not using the dummy paths will be a very common error. Gantt chart took too long. f) and g) will be poorly answered.

Overall I would say it was a little easier than Jan, I would expect it to be around 63 for an A.

This summer I will upload solutions to the following Edexcel papers:

Core 1;
Core 2;
Core 3;
Core 4;
FP1;
M1;
M2;
S1;
D1;
D2.

I will try to get hold of some solutions for FP2; FP3 and M3.

I don't do S2 :frown:

All papers will be uploaded in line with site rules (please don't PM me asking when I will I be uploading them).

On the linear programming, shouldnt it be the other way around?
Y=300 and x= 100 therefore the objective line will go through (20,60)

????

Reply 111

niki135

Original post by alexandraa

Niki153: not answering your questions but I just majorly goofed up s1 and I feel exactly the same way as you!!

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Ah I hope we didn't do that bad and still manage to get our A! From what my friends were telling me, S1 started off well but got harder at the end. Hopefully boundaries are low!

Reply 112

dav22

Original post by Harryg_95

On the linear programming, shouldnt it be the other way around?
Y=300 and x= 100 therefore the objective line will go through (20,60)

????

It's 100x + 300y so you found a common multiple e.g
100x + 300y = 30000 then make both 0 meaning
300y = 30000 therefore y = 100 and
100x = 30000 therefore x = 300
then you have (300,100) and you cancel it down so it fits on the graph, so divide both sides by 5 giving (60,20)

Reply 113

lebron_23

Original post by wndms

That's exactly how I feel about M1 I sat on Monday :frown:

But don't worry. You need 480/600 UmS to get an A. If you get over 90% for C3 C4 you can get an A*

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Ah yes I know, core maths won't be a problem at all as they'll put in my best marks for that, meaning I'll be on a high A. The horrible bit is, I have to apply to uni with a B (and that's the VERY best case scenario) overall in further maths. I flopped that paper so badly that I'm still actually in shock. It's like it hasn't sunk in because every time I think about it, it just seems so comical. Yesterday literally shattered my life.

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Reply 114

wndms

Original post by lebron_23

I know, I'm worried now :frown:

if I don't get 90% in my C4, I will miss my A* so my Maths and F Maths grades will become Bs because that s***ty M1 grade will cash in towards f maths

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Reply 115

moko

so what are the grade boundaries for this?

Reply 116

Neonnoon

Do you think they'd accept that at most two fifths of the boats made should be small boats? It's the only answer I think is wrong. 😕

Reply 117

niki135

Original post by m4ths/maths247

Arsey I am happy to remove the link if you dont want it on the thread :smile:

Sir, please could you answer these quick questions for me!

- for the linear programming I didn't have enough time so I only drew one of the constraints... How many marks will I get? If any..
- for the Gantt chart I didn't use the ruler for some, I had no time left, but they were straight-ish lines... Will that be okay?
- I drew a line on the chart and just wrote 5 (not 5 workers, just 5 haha), for the number of workers! I didn't have time to write anything else. Will that even be a mark?

Thank you xx

Reply 118

dying-divinity

Oh dear, I completely didn't read the question to write out the route but at least I put the length.
Minus 1 or 2 marks there :frown:

But overall I think this paper went pretty well :smile:

Easier paper than I was expecting. Thanks so much for the solutions! :smile:

Reply 119

daksesh

For the linear programming question part d) I got the values as x=54 and y=36 and the minimum cost as £16200. However i didn't write a sentence that he should buy 54 two seater boats and 36 four seater boats. So how many marks will i get for that part.