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*Rough*DECISION 1 EDEXCEL JUNE 17TH MARKSCHEME w/Explained Answers Watch

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    (Original post by Nikhilm)
    I'm pretty sure you could've done it in 4 bins not 5?


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    I ended up with 4 bins
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    (Original post by FugFig)
    Nah i am pretty sure now its 65. 75 was the second smallest pair, and for the 65 the path was tricky, so i think the others just didnt see it.(at least i hope so)
    Yeah the path for 75 was ridiculous, pretty sure I ****ed up that whole question
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    Also, if I got the objective function wrong (which is obviously -1 mark), are there ecf marks for the next question?
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    (Original post by ediosaurus)
    In some papers you get penalised 1 mark
    My teacher told me that u won't but idk tbh
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    I've just read a past mark scheme and it says 'condone lack of numbers', just as long as you don't put activities in the nodes...
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    How many marks were questions 2, 7 and 8?
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    (Original post by Dannyfire)
    How many marks were questions 2, 7 and 8?
    5 11 and 14
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    (Original post by TrueDAN)
    Getting on this one as fast as possible. I hated this exam, everyone else found it good - maybe decision maths isn't for me but it'll be nice to see how your answers compare.

    Question 1:
    - A bipartite graph consists of 2 vertices, X and Y. Vertices can only be joined from X to Y, not joined from the same set I.e. X to X.
    - It was the most confusing / long winded route I got it as. You were matching P with B.
    P-A = ..... M - B and change state.

    Question 2:
    - Precedence table was with 3 dummies. I did get a nice looking one but I know I made one mistake. C and D were dependent on A. E and F were dependent on B. A and B were dependent on nothing and came from a node labelled O.
    Remember to link the all up at the end to create a nice network.

    Question 3:
    - Quicksort with 10 numbers. I can remember 11 being shifted to the very end after the first pass. Make sure to label pivots clearly and to say that the source is complete.
    - First fit decreasing got you 4 bins.
    - Lowerbound was 4, the question was asking if it was optimal. Therefore, it was optimal.

    Question 4:
    - Ouput 135 implying 7 and 25 were multiplied together.
    - 122 because using 1/2 would encounter negatives.
    - 122 X 1/2 = 61.

    Question 5:
    Worried about this one - can't remember it well.
    - 48 units in length.
    - One with J 49 units in length.
    - Missed out Prim's question and only noticed at end so rushed like mad - I got 87.
    Answer is 82 I believe.
    Question 6: Chinese postman
    - Weight 459 but I put 460
    - Look at one excluding F which was EH and 35 in length.
    - 419 with a route with 21 nodes, starting at F and finishing at B.

    Question 7:
    - for answers of w,X,y,z (not in order) 4,11,17 and 22?
    - Gantt chart - hate you - you had 4 critical values. I got 6.
    - 5 workers as lower bound looking at day 12-14
    - Scheduling = ran out of time / didn't bother really.

    Question 8:
    - 20x + 65y less than or equal to 520.
    - Remember that X.y larger than equal to 0. Plot the points to get a region R - one of the equations I struggled with and I think it was something like:
    -X + 24y larger than or equal to 24. I brought the X over and got 0,0 and 0,1 as my points. I don't think it interfered with the region - I may have got it wrong please tell me.
    - Exact values you had to look at the point of intersection between 7x + 8y = 120 and 20x + 65y = 520.
    I did simultaneous equations and got fractions - I checked there decimal points and it did look close to where V was. I got V to be the upper, right hand side point.

    9 and 4 I got for the crates
    People got 9 and 5
    I ink the correct is 11 and 4.
    I think I've done horribly on this paper, please help me add on to it to create a nice markscheme! I really wanted an A overall, think I may have not done enough in this module. Anywho, I will update ASAP and try my best to respond quickly. Good luck all

    For Algorithm one, some people say because 1/2 for X will give a never ending result as u'd keep halving the X value ( giving: -/2 -/4 -/8 -/16 ....)

    I agree with it even though I didn't get in the exam
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    (Original post by lucabrasi98)
    They do lol. It says so on the front page

    Only an idiot draws diagrams in pen anyway
    Umm... I guess I was one ( with the amount of TIME we had to swap pens)
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    last question: 9x and 5y giving maximum capacity given the budget of 520 as it cost a total of 505
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    What do you think the grade boundaries will be like? I totally screwed up this paper and I need an A overall, I guess I'm just going to have to ace C3 and C4 lol
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    For part 2 of the flowchart was the reason not because a fraction can be neither odd or even?
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    (Original post by sadasad)
    last question: 9x and 5y giving maximum capacity given the budget of 520 as it cost a total of 505

    that doesn't fit the constraint of 7x+8y<112
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    Prims was 69 or 70?
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    (Original post by brokeins1)
    For Algorithm one, some people say because 1/2 for X will give a never ending result as u'd keep halving the X value ( giving: -/2 -/4 -/8 -/16 ....)

    I agree with it even though I didn't get in the exam
    Oh yes I suppose - grrr another 2 marks I may have dropped. But wasn't the input of the algorithm:
    Is X odd
    If yes, X = X-1
    So inputting 1/2 would take you to that procedure which encounters negatives? Cannot remember it well enough
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    (Original post by s0phi33)
    What do you think the grade boundaries will be like? I totally screwed up this paper and I need an A overall, I guess I'm just going to have to ace C3 and C4 lol
    I wanted high 60s in that test and have came out with high 40s Certainly lower than normal, do not think a lot of people will have got over 60 in it due to the time constraints. I do not want to speculate, but I could not see an A being over 60 at all. Maybe even 55, who knows - just smash C3 and C4 and do not worry about D1 It was not a test of how good you are at maths at all - really disappointing exam.
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    Doesnt anyone have a copy of the paper?!!!!!
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    (Original post by TrueDAN)
    Oh yes I suppose - grrr another 2 marks I may have dropped. But wasn't the input of the algorithm:
    Is X odd
    If yes, X = X-1
    So inputting 1/2 would take you to that procedure which encounters negatives? Cannot remember it well enough
    I guess you have to realate it to the diffenition of an algorithm being finite, and so wouldn't be in thiscase where you have 1/2 =x. OR with this value u'd get a wrong output ( a negative answer, whereas xy= +61

    Btw was it not 1 mark?????
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    So no one had a copy of the paper then?
 
 
 
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