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

1. (Original post by Fortitude)
Ha ha your way of explaining was way better than mine & I chose 3x + 2y as well but for integer solutions there must be a quicker way, there has to be!
Yh I think typically you can just look at the graph and figure out yourself which points will be feasible! which is probably what I will do... Though if you get time to check your paper (god knows who will ), that would be a good way to check your right. & that your chosen point is in feasible region.

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2. (Original post by otrivine)
yay
this is our syllabus for linear
5 Linear programming
What students need to learn:
Formulation of problems as linear programs.
Graphical solution of two variable problems using
ruler and vertex methods
Consideration of problems where solutions must
have integer values

we only have 2 variables not 3
Ah great ! Thank-you for looking that up.... *phew*
3. (Original post by posthumus)
Yh I think typically you can just look at the graph and figure out yourself which points will be feasible! which is probably what I will do... Though if you get time to check your paper (god knows who will ), that would be a good way to check your right. & that your chosen point is in feasible region.

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Yep, I think timing is very important in this exam, we got suggested to do linear programming & basically the 'big' questions first but not sure that would be a good idea
4. (Original post by Fortitude)
Yep, I think timing is very important in this exam, we got suggested to do linear programming & basically the 'big' questions first but not sure that would be a good idea
I am very bad with remembering definitions - so personally I'm going to be reciting all definitions in my head as I walk into the hall .... and get those questions out of the way first (if there are any - which I hope there won't be!)
5. (Original post by posthumus)
Ah great ! Thank-you for looking that up.... *phew*
It says 2 variables graphical right? Don't want to get it wrong, so it's not 3 from what I copied and paste?
6. (Original post by posthumus)
I am very bad with remembering definitions - so personally I'm going to be reciting all definitions in my head as I walk into the hall .... and get those questions out of the way first (if there are any - which I hope there won't be!)
Yeah, they're annoying & can cost precious marks, if they do come up, I hope they're the easier ones But what I really don't like are the 'wordy' parts of the questions like what would happen if...or trying to find the route for route inspection, it takes me ages!!
7. (Original post by otrivine)
It says 2 variables graphical right? Don't want to get it wrong, so it's not 3 from what I copied and paste?
It's most definitely not 3
8. (Original post by Fortitude)
Yeah, they're annoying & can cost precious marks, if they do come up, I hope they're the easier ones But what I really don't like are the 'wordy' parts of the questions like what would happen if...or trying to find the route for route inspection, it takes me ages!!
Oh I hate the "what would happen if... " questions too I hope those"if" questions aren't applied to linear programming or critical path analysis... as I haven't done any of those kind of questions Though I think I do remember 1 or 2 for linear programming when I was studying for D1 in Jan, in the Edexcel book, but not in past papers
9. (Original post by Fortitude)
It's most definitely not 3
Hi can you or anyone explain Question 6)a

Don't get the wording thanks
10. (Original post by otrivine)
Hi can you or anyone explain Question 6)a

Don't get the wording thanks
Hi, where is 6a?
11. (Original post by Fortitude)
Hi, where is 6a?
Mixed exercise 1F
12. (Original post by otrivine)
Mixed exercise 1F
Ok, this is a tricky one but I'll try my best...
He needs 2 pieces which are each 1.2m so as he has 6 2m pieces he could use 2 of them to cut 1.2m out now this will leave 0.8m of wood in each & the only way to use that 0.8 is to have 2 pieces of 0.4 h/w this will only work w/ one piece as he only wants 3x0.4 pieces so in the other piece there will 0.4m left that will be of no use so overall he will need more than 6 lengths, hope that makes sense!
13. (Original post by otrivine)
Mixed exercise 1F
If you use the full bin packing algorithm with 6 bins of 2m each you'll find that it doesn't fit. I can't think of a way to explain it though.
14. I'm pretty sure this will be a 'walk in the park'
15. Some decent notes here, guys.

It does have some old syllabus stuff in, though.
Attached Files
16. Decision Mathematics 12.ppt (2.00 MB, 203 views)
17. (Original post by Dilzo999)
If you use the full bin packing algorithm with 6 bins of 2m each you'll find that it doesn't fit. I can't think of a way to explain it though.
so for part a should I use full bin, I thought part c required us to do full bin
18. When drawing activity networks, do you start from 0 or 1?
19. (Original post by IWantSomeMushu)
Some decent notes here, guys.

It does have some old syllabus stuff in, though.
may i confirm with you, in your notes you had linear programming with 3 variables , thats not in our syllabus.

Very nice notes 10/10
20. (Original post by Fortitude)
When drawing activity networks, do you start from 0 or 1?
you start from 0.

I still dont get 6)a)
21. (Original post by otrivine)
may i confirm with you, in your notes you had linear programming with 3 variables , thats not in our syllabus.

Very nice notes 10/10
Yeah, simplex was in the old syllabus. I think it's in D2 now.

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