Arsey's D2 June 2013 Edexcel (UK+International) Solutions (in the first post)

My solutions to the June 2013 D2 (UK version) will be posted shortly. I may upload solutions to the International paper later today (Friday)

If I don't answer a question directed at me please do not get upset, any of the following could apply:

I might be busy;
your post might be too long;
I may not know the answer;
I may know the answer but have already answered the same question.

(take a few minutes to read the previous posts before asking a question)

I have turned off PMs, so your only option is to ask here. I had no choice but to turn off PMs due to daft messages/questions from muppets.

The grade boundaries will be primarily based upon how candidates have performed in the exam. There is NO point asking what would x / 75 be worth, no one knows. The boundaries will be released a day or two before results day. Official mark schemes will be released in July.

You require 240/300 UMS for an A in AS Maths / Further Maths

You require 480/600 UMS for an A in A2 Maths / Further Maths

You require 480/600 + 180/200 in C3/C4 for an A* in A2 Maths

You require 480/600 + 270/300 in your 3 best units* for an A* in A2 Further (*not inc FP1, D1, S1, M1 or C1-4).

D2 Paper Analysis

This paper was pure filth, the only good thing was the next instalment of Agent Goodie's adventures.

Q1. TSP - It wasn't too bad but to get an optimal solution was rather odd

Q2. Transportation - Both stepping stones were horrible.

(you don't need the costs after each improved solution)>

Q3. Flows - Not too bad, quite nice. However, it was possible to get a fake min-cut, a bit naughty!

Q4. Game Theory - Harder than normal

Q5. Simplex - Quite nice, numbers were not horrible. Although, it was strange that it started after one iteration had already been done.

Original post by Arsey

Original post by Hamburglar

However, upon a quick scan I disagree with your answer to 5a. It says state which variable WAS increased first, because an iteration had already been done. I put z because this column has zeros in it, which suggested the variables for this had been eliminated and the 1 suggests that, that was the pivot being used.

good spot, I misread the question. Clearly z WAS increased first. I didn't notice an iteration had already been done until afterwards.

Q6. Allocation and LP - A Maximising Allocation LP question, without part a) it would have been a bloodbath. Part a) may save a few

Q7. Dynamic Programming - Horrible question, I think the way they set out the table was really confusing - EPIC BLOODBATH

Boundaries



Module    Session    100'    90'    80'    70'    60'    50'    40'
D2    Jun-12    75    69.5    64    54    44    35    26
D2    Jun-11    75    69.5    64    55    46    38    30
D2    Jun-10    75    68.0    61    52    44    36    28
D2    Jun-09    73    65.0    57    49    41    34    27

No idea about boundaries for this paper; although, I would be surprised if it is too far away from 60. I would guess at 60 for an A.

I have now added the solutions to the International paper. It was very easy in comparison to the UK paper :angry:

(edited 10 years ago)

13 June D2 Model UK red3.pdf926.7KB

13 June D2 Int Model red 3.pdf698.2KB

Reply 1

Hamburglar

Original post by Arsey

My solutions to the June 2013 M2 (UK version) will be posted shortly. I may upload solutions to the International paper later today (Friday)

If I don't answer a question directed at me please do not get upset, any of the following could apply:

I might be busy;
your post might be too long;
I may not know the answer;
I may know the answer but have already answered the same question.

(take a few minutes to read the previous posts before asking a question)

I have turned off PMs, so your only option is to ask here. I had no choice but to turn off PMs due to daft messages/questions from muppets.

The grade boundaries will be primarily based upon how candidates have performed in the exam. There is NO point asking what would x / 75 be worth, no one knows. The boundaries will be released a day or two before results day. Official mark schemes will be released in July.

You require 240/300 UMS for an A in AS Maths / Further Maths

You require 480/600 UMS for an A in A2 Maths / Further Maths

You require 480/600 + 180/200 in C3/C4 for an A* in A2 Maths

You require 480/600 + 270/300 in your 3 best units* for an A* in A2 Further (*not inc FP1, D1, S1, M1 or C1-4).

D2 Paper Analysis

This paper was pure filth, the only good thing was the next instalment of Agent Goodie's adventures.

Q1. TSP - It wasn't too bad but to get an optimal solution was rather odd

Q2. Transportation - Both stepping stones were horrible.

(you don't need the costs after each improved solution)>

Q3. Flows - Not too bad, quite nice. However, it was possible to get a fake min-cut, a bit naughty!

Q4. Game Theory - Harder than normal

Q5. Simplex - Quite nice, numbers were not horrible. Although, it was strange that it started after one iteration had already been done.

Q6. Allocation and LP - A Maximising Allocation LP question, without part a) it would have been a bloodbath. Part a) may save a few

Q7. Dynamic Programming - Horrible question, I think the way they set out the table was really confusing - EPIC BLOODBATH

Nice one Arsey! Cheers.

However, upon a quick scan I disagree with your answer to 5a. It says state which variable WAS increased first, because an iteration had already been done. I put z because this column has zeros in it, which suggested the variables for this had been eliminated and the 1 suggests that, that was the pivot being used.

Reply 2

Matt_payne

I think 5a) is wrong, was *increased* first

Posted from TSR Mobile

Reply 3

Hamburglar

Original post by Arsey

My solutions to the June 2013 M2 (UK version) will be posted shortly. I may upload solutions to the International paper later today (Friday)

If I don't answer a question directed at me please do not get upset, any of the following could apply:

I might be busy;
your post might be too long;
I may not know the answer;
I may know the answer but have already answered the same question.

(take a few minutes to read the previous posts before asking a question)

I have turned off PMs, so your only option is to ask here. I had no choice but to turn off PMs due to daft messages/questions from muppets.

The grade boundaries will be primarily based upon how candidates have performed in the exam. There is NO point asking what would x / 75 be worth, no one knows. The boundaries will be released a day or two before results day. Official mark schemes will be released in July.

You require 240/300 UMS for an A in AS Maths / Further Maths

You require 480/600 UMS for an A in A2 Maths / Further Maths

You require 480/600 + 180/200 in C3/C4 for an A* in A2 Maths

You require 480/600 + 270/300 in your 3 best units* for an A* in A2 Further (*not inc FP1, D1, S1, M1 or C1-4).

D2 Paper Analysis

This paper was pure filth, the only good thing was the next instalment of Agent Goodie's adventures.

Q1. TSP - It wasn't too bad but to get an optimal solution was rather odd

Q2. Transportation - Both stepping stones were horrible.

(you don't need the costs after each improved solution)>

Q3. Flows - Not too bad, quite nice. However, it was possible to get a fake min-cut, a bit naughty!

Q4. Game Theory - Harder than normal

Q5. Simplex - Quite nice, numbers were not horrible. Although, it was strange that it started after one iteration had already been done.

Q6. Allocation and LP - A Maximising Allocation LP question, without part a) it would have been a bloodbath. Part a) may save a few

Q7. Dynamic Programming - Horrible question, I think the way they set out the table was really confusing - EPIC BLOODBATH

Nice one Arsey! Cheers.

However, upon a quick scan I disagree with your answer to 5a. It says state which variable WAS increased first, because an iteration had already been done. I put z because this column has zeros in it, which suggested the variables for this had been eliminated and the 1 suggests that, that was the pivot being used.

Also, I made an error on the last question pretty early on. My method was spot on and my layout was exactly like yours, but I think I forgot to add the destinations on or something pretty early on. Please can you tell me how many marks I will lose for this? Thanks :frown:

Reply 4

tea_light

I agree that 5a is incorrect.

Thank you, I do have one question;

Concerning question 6,

a) I took all values away from 258, as the thought of a '0' cell in the latter LP worried me. I've noticed that edexcel accept it as along as we take all values from some n=>max value (in this case 257). So the first parts right I assume.

b) However, it follows that my objective function is defined with different coefficients to those of yours, in face they're all (+1). Is this still correct? It would seem a contradiction to allow part 'a' and not 'b' right?

Yours gratefully,

Jake.

(edited 10 years ago)

Reply 5

Matt_payne

Original post by tea_light

I agree that 5a is incorrect.

Thank you, I do have one question;

Concerning question 6,

a) I took all values away from 258, as the thought of a '0' cell in the latter LP worried me. I've noticed that edexcel accept it as along as we take all values from some n=>max value (in this case 257). So the first parts right I assume.

b) However, it follows that my objective function is defined with different coefficients to those of yours, in face they're all (+1). Is this still correct? It would seem a contradiction to allow part 'a' and not 'b' right?

Yours gratefully,

Jake.

I did that too, it should be fine! :smile:

Posted from TSR Mobile

Reply 6

tea_light

Original post by Matt_payne

I did that too, it should be fine! :smile:

Posted from TSR Mobile

Ah thank you, that is somewhat of a relief!

Reply 7

Matt_payne

Original post by tea_light

Ah thank you, that is somewhat of a relief!

I'm not certain it's right, but it should be haha

Posted from TSR Mobile

Reply 8

BobLoblawLawBlog

16

Original post by Arsey

My solutions to the June 2013 D2 (UK version) will be posted shortly. I may upload solutions to the International paper later today (Friday)

If I don't answer a question directed at me please do not get upset, any of the following could apply:

I might be busy;
your post might be too long;
I may not know the answer;
I may know the answer but have already answered the same question.

(take a few minutes to read the previous posts before asking a question)

I have turned off PMs, so your only option is to ask here. I had no choice but to turn off PMs due to daft messages/questions from muppets.

The grade boundaries will be primarily based upon how candidates have performed in the exam. There is NO point asking what would x / 75 be worth, no one knows. The boundaries will be released a day or two before results day. Official mark schemes will be released in July.

You require 240/300 UMS for an A in AS Maths / Further Maths

You require 480/600 UMS for an A in A2 Maths / Further Maths

You require 480/600 + 180/200 in C3/C4 for an A* in A2 Maths

You require 480/600 + 270/300 in your 3 best units* for an A* in A2 Further (*not inc FP1, D1, S1, M1 or C1-4).

D2 Paper Analysis

This paper was pure filth, the only good thing was the next instalment of Agent Goodie's adventures.

Q1. TSP - It wasn't too bad but to get an optimal solution was rather odd

Q2. Transportation - Both stepping stones were horrible.

(you don't need the costs after each improved solution)>

Q3. Flows - Not too bad, quite nice. However, it was possible to get a fake min-cut, a bit naughty!

Q4. Game Theory - Harder than normal

Q5. Simplex - Quite nice, numbers were not horrible. Although, it was strange that it started after one iteration had already been done.

Q6. Allocation and LP - A Maximising Allocation LP question, without part a) it would have been a bloodbath. Part a) may save a few

Q7. Dynamic Programming - Horrible question, I think the way they set out the table was really confusing - EPIC BLOODBATH

Boundaries



Module    Session    100'    90'    80'    70'    60'    50'    40'
D2    Jun-12    75    69.5    64    54    44    35    26
D2    Jun-11    75    69.5    64    55    46    38    30
D2    Jun-10    75    68.0    61    52    44    36    28
D2    Jun-09    73    65.0    57    49    41    34    27

No idea about boundaries for this paper; although, I would be surprised if it is too far away from 60. I would guess at 60 for an A.

Thank you for this! PRSOM.

On the Dynamic programming question, I got the right order (Keep, Keep, Replace, Keep), but my income was only £29000. I know the no. marks I lose will depend on where I went wrong, but I know a few other people that got this same answer and so it may be a fairly common incorrect answer. If so, do you know how many marks this would lose? Thanks.

Edit: I'm loving the smiley face next to Agent Goodie :biggrin:

.

(edited 10 years ago)

Reply 9

dannyboy819

Original post by Arsey

My solutions to the June 2013 D2 (UK version) will be posted shortly. I may upload solutions to the International paper later today (Friday)

If I don't answer a question directed at me please do not get upset, any of the following could apply:

I might be busy;
your post might be too long;
I may not know the answer;
I may know the answer but have already answered the same question.

(take a few minutes to read the previous posts before asking a question)

I have turned off PMs, so your only option is to ask here. I had no choice but to turn off PMs due to daft messages/questions from muppets.

The grade boundaries will be primarily based upon how candidates have performed in the exam. There is NO point asking what would x / 75 be worth, no one knows. The boundaries will be released a day or two before results day. Official mark schemes will be released in July.

You require 240/300 UMS for an A in AS Maths / Further Maths

You require 480/600 UMS for an A in A2 Maths / Further Maths

You require 480/600 + 180/200 in C3/C4 for an A* in A2 Maths

You require 480/600 + 270/300 in your 3 best units* for an A* in A2 Further (*not inc FP1, D1, S1, M1 or C1-4).

D2 Paper Analysis

This paper was pure filth, the only good thing was the next instalment of Agent Goodie's adventures.

Q1. TSP - It wasn't too bad but to get an optimal solution was rather odd

Q2. Transportation - Both stepping stones were horrible.

(you don't need the costs after each improved solution)>

Q3. Flows - Not too bad, quite nice. However, it was possible to get a fake min-cut, a bit naughty!

Q4. Game Theory - Harder than normal

Q5. Simplex - Quite nice, numbers were not horrible. Although, it was strange that it started after one iteration had already been done.

Q6. Allocation and LP - A Maximising Allocation LP question, without part a) it would have been a bloodbath. Part a) may save a few

Q7. Dynamic Programming - Horrible question, I think the way they set out the table was really confusing - EPIC BLOODBATH

Boundaries



Module    Session    100'    90'    80'    70'    60'    50'    40'
D2    Jun-12    75    69.5    64    54    44    35    26
D2    Jun-11    75    69.5    64    55    46    38    30
D2    Jun-10    75    68.0    61    52    44    36    28
D2    Jun-09    73    65.0    57    49    41    34    27

No idea about boundaries for this paper; although, I would be surprised if it is too far away from 60. I would guess at 60 for an A.

Thanks Arsey, I always value the effort you put into these solutions and the reassurance they bring me, but I agree with the previous person who about 5a as it said was

Reply 10

Arsey

OP

10

Original post by Hamburglar

Nice one Arsey! Cheers.

However, upon a quick scan I disagree with your answer to 5a. It says state which variable WAS increased first, because an iteration had already been done. I put z because this column has zeros in it, which suggested the variables for this had been eliminated and the 1 suggests that, that was the pivot being used.

good spot, I misread the question. Clearly z WAS increased first. I didn't notice an iteration had already been done until afterwards.

Reply 11

Arsey

OP

10

Original post by tea_light

I agree that 5a is incorrect.

Thank you, I do have one question;

Concerning question 6,

a) I took all values away from 258, as the thought of a '0' cell in the latter LP worried me. I've noticed that edexcel accept it as along as we take all values from some n=>max value (in this case 257). So the first parts right I assume.

b) However, it follows that my objective function is defined with different coefficients to those of yours, in face they're all (+1). Is this still correct? It would seem a contradiction to allow part 'a' and not 'b' right?

Yours gratefully,

Jake.

nah, this is fine. you can subtract from any value bigger than 257.

Reply 12

Jakegt1

4

On question 8, i forgot to add 11 to the final box on year 1. (so i had 21 instead of 32)
How many marks do you think i would lose? 1 or 2?

Reply 13

Arsey

OP

10

Original post by brittanna

Thank you for this! PRSOM.

On the Dynamic programming question, I got the right order (Keep, Keep, Replace, Keep), but my income was only £29000. I know the no. marks I lose will depend on where I went wrong, but I know a few other people that got this same answer and so it may be a fairly common incorrect answer. If so, do you know how many marks this would lose? Thanks.

Edit: I'm loving the smiley face next to Agent Goodie :biggrin:

.

no idea, I have no idea how what caused the 29 (000) error

Reply 14

Hamburglar

Original post by Arsey

good spot, I misread the question. Clearly z WAS increased first. I didn't notice an iteration had already been done until afterwards.

That's alright :smile:

Huh, my post didn't appear to you, weird. I was just wondering if you could reassure me a bit please?

On the dynamic programming, I had the exact same layout as you and the same method and everything. But I got Keep, Keep, Keep, Replace with a profit of 29k.

I think I might have made a mistake early on by not adding on one of the destination profits or something.

Please can you tell me how this'll impact my mark? I don't want to lose too many out of 13 :s

Thanks

Reply 15

Arsey

OP

10

Original post by Jakegt1

On question 8, i forgot to add 11 to the final box on year 1. (so i had 21 instead of 32)
How many marks do you think i would lose? 1 or 2?

at least 2, could be more.

Reply 16

Jakegt1

4

Maximum 4? Seems alright, i did really well on this paper anyway. What do you think 90 ums might be? I think the only other mark i've dropped is the cut (71) for the flows, maybe one or two on the linear programming too.

Reply 17

Caramelapps

2

Oh... On the simplex, I got z=33 instead of 37. So I suppose 1 or 2 marks lost for that :s-smilie:

and I was so hoping that would be my first 100% oh well. Thanks Arsey for the solutions :biggrin:

Reply 18

Arsey

OP

10

Original post by Hamburglar

That's alright :smile:

Huh, my post didn't appear to you, weird. I was just wondering if you could reassure me a bit please?

On the dynamic programming, I had the exact same layout as you and the same method and everything. But I got Keep, Keep, Keep, Replace with a profit of 29k.

I think I might have made a mistake early on by not adding on one of the destination profits or something.

Please can you tell me how this'll impact my mark? I don't want to lose too many out of 13 :s

Thanks

The earlier the error the more marks you will probably lose unfortunately. It seems quite arbitrary when they allow f.t. marks, clearly you will get the method marks whenever your method was correct. But you will lose the method mark in your error, the accuracy mark in your error, you will then lose other accuracy marks inc the final solution.

I think if you've lost just 5 you should be happy.