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# D1 (Decision 1) 17 May 2013 Official Thread Watch

1. (Original post by Vaner)
Assume in Linear Programming the optimal point lies on a dotted line ( < or > inequality ) , do I take the exact point? Or up/down it?
The point you choose must be in inside R. If the line is dotted so that the line is not part of R, then you'll need to find a point that is. This would only be a sensible question if you needed integer values so that you know which the next point is.
2. (Original post by Vaner)
If X lies between 40 and 20 for example, do I use bigger/smaller sign or bigger/smaller and equal sign?
Depends on the wording. If it says "between 40 and 20 inclusive" then you need less than or equal to signs. In the past they have sometimes accepted either if it wasn't obvious from the wording.
3. (Original post by otrivine)
Thanks and in route inspection if in mark scheme they put

BC + GH
BG + CH
BH + CG

and if I did this

CB + GH
CG+ HB
CH + GB

does this mean the same thing right?
Yes it does.
4. (Original post by otrivine)
Thanks and do you get this question http://www.edexcel.com/migrationdocu...s_20110817.pdf
7)e) right, why did they do 3 x 9 =27 days work, why are there 9 activities when its 8 ?

thanks again
From 7 to 16 is a 9 hour gap. 3 workers could therefore do 27 hours of work. However, during that period, C D E F G H and I must all happen as well as 4 hours of J. Adding up the duration of those activities comes to 31 hours, so too much for 3 workers.
5. The exam style paper at the back of the book is easier than all the past papers right?
6. I'm ready to kick D1's ass on Friday, hopefully it will go better than M1 today!
7. Hey when shading the region do you guys shade all of it or can u just do the sort of stripes shading?

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8. Sorry everything that's not in the region

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9. (Original post by Flounder1)
Hey when shading the region do you guys shade all of it or can u just do the sort of stripes shading?

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Usually I just do little scribbles, but personally in the exam I don't think it takes too long to shade it, so I do shade it nicely Though if you think that will waste time then don't !

Some minor scribbling or stripes would be fine, as long as its obvious that its the unwanted region
10. Yup D1 is easy all I hate is the definition ugh they annoy me. I just hate remembering things word for word.
11. (Original post by Flounder1)
Sorry everything that's not in the region

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I show you what I mean:

Edit: Apoligies for the drawing, Im in a rush to get to class lol
Attached Images

12. i have got an A in C1-3 and S1, so i think i only need like 40% overall to get an A
13. (Original post by Zzzyax)
i have got an A in C1-3 and S1, so i think i only need like 40% overall to get an A
I'm not sure that's the right attitude to go into any A-Level Exams.

Re-doing some D1 Papers now. Can anyone help with a quick question:

In Gantt Chants will you be deducted marks if you do not do Activities with the earliest finish time first???? (Excluding Critical Activities?)
14. (Original post by tiny hobbit)
From 7 to 16 is a 9 hour gap. 3 workers could therefore do 27 hours of work. However, during that period, C D E F G H and I must all happen as well as 4 hours of J. Adding up the duration of those activities comes to 31 hours, so too much for 3 workers.
I just did that Paper now.

Surprisingly made so many mistakes. It is extremely frustrating That question stumped me though. Just got 60/75. Argh! Well at least I learnt some great lessons in reading carefully on Critical Path Analysis Questons!!

And on Route Inspection it seem to make the mistake of finding the wrong shortest paths. I must remember that the Final Working on the node is the shortest Route to that Node!!!

Only 3 more Papers to Re-do tonight!!! Hopefully I can get A*s in these ones
15. (Original post by Better)
I'm not sure that's the right attitude to go into any A-Level Exams.

Re-doing some D1 Papers now. Can anyone help with a quick question:

In Gantt Chants will you be deducted marks if you do not do Activities with the earliest finish time first???? (Excluding Critical Activities?)
I don't think the order matters in a Gantt chart... though in the mark scheme they always have it in alphabetical order I believe (apart from critical analysis of course)
16. what is the order of difficulty of the chapters of this book?
17. which paper was the hardest for D1?
18. If i don't get an A this time i think i will use prims algorithm to find the shortest route to the nearest tall building then jump off it.
19. (Original post by Season One)
If i don't get an A this time i think i will use prims algorithm to find the shortest route to the nearest tall building then jump off it.
haha dont say that you will be fine
20. (Original post by Season One)
If i don't get an A this time i think i will use prims algorithm to find the shortest route to the nearest tall building then jump off it.
If you don't get an A, then how would you possibly be able to perform Prim's algorithm ?

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