Edexcel D1 - 17th June, 2016 [Exam discussion]

OP

Hey guys Im about to start doing past papers for D1 now.

Just wondering, there was a spec change in 2009 which meant that we can only do past papers for FP1 from 2009 onwards.

From looking at past papers, it seems the same happened for D1. Can anyone confirm if Im right in saying that the D1 papers from Jan 2009 onwards are okay to do? The past papers before that will be different?

Thanks

Reply 41

tiny hobbit

15

Original post by GarlicBread01

Hey guys Im about to start doing past papers for D1 now.

Just wondering, there was a spec change in 2009 which meant that we can only do past papers for FP1 from 2009 onwards.

From looking at past papers, it seems the same happened for D1. Can anyone confirm if Im right in saying that the D1 papers from Jan 2009 onwards are okay to do? The past papers before that will be different?

Thanks

The ones before Jan 2009 included Simplex, flows in networks and the planarity algorithm. These topics are now in D2. The other questions on the papers for 2001 to 2008 are on the same topics as the current papers.

Reply 42

GarlicBread01

OP

11

Original post by tiny hobbit

The ones before Jan 2009 included Simplex, flows in networks and the planarity algorithm. These topics are now in D2. The other questions on the papers for 2001 to 2008 are on the same topics as the current papers.

Okay, Ill do the ones after Jan 2009

Thanks ^_^

Reply 43

techfan42

4

Guys, could someone please explain how to construct a scheduling diagram without drawing a Gantt chart?

Reply 44

techfan42

4

^ for this question specifically

scheduling diagram.jpg85.7KB

Reply 45

tiny hobbit

15

Original post by techfan42

^ for this question specifically

In order to finish in a time of 30 or with a restricted number (2) of workers?

Reply 46

nathanbilli

1

Does anyone know where to find the definitions we need for the exam :smile:

Reply 47

NotNotBatman

20

Original post by nathanbilli

Does anyone know where to find the definitions we need for the exam :smile:

Last page.

http://www.waldomaths.com/docs/edex/D1_Edex_6689_Spec.pdf

Reply 48

nathanbilli

1

Original post by NotNotBatman

Last page.

http://www.waldomaths.com/docs/edex/D1_Edex_6689_Spec.pdf

Thanks

Reply 49

Glavien

11

For question 7 (g) of the January 2013 paper, how would you know what the minimum number of workers are, what would be your thought process?

Reply 50

NotNotBatman

20

Original post by Glavien

For question 7 (g) of the January 2013 paper, how would you know what the minimum number of workers are, what would be your thought process?

Draw a line or just use your ruler where most of the boxes on the gantt chart overlap, the number of activites that lie on that line is the min number of workers.

Reply 51

Glavien

11

Original post by NotNotBatman

Draw a line or just use your ruler where most of the boxes on the gantt chart overlap, the number of activites that lie on that line is the min number of workers.

Thanks!

Reply 52

Glavien

11

Can someone explain question 3 (b) of the January 2013 paper I don't understand the MS. Do you look at the given matching and see if there is a match for each person? What would be the simplest way of approaching the question?

Reply 53

NotNotBatman

20

Original post by Glavien

Can someone explain question 3 (b) of the January 2013 paper I don't understand the MS. Do you look at the given matching and see if there is a match for each person? What would be the simplest way of approaching the question?

Look at the matches for each activity and notice that activity 5 and 1 can only be done by G, since G can't do more than one activity, a complete matching is not possible.

Reply 54

Glavien

11

Original post by NotNotBatman

Look at the matches for each activity and notice that activity 5 and 1 can only be done by G, since G can't do more than one activity, a complete matching is not possible.

Ohhh, got it thank you. :smile:

Reply 55

Glavien

11

For question 4 of the June 2013 R paper, how come you need to rearrange the list in order to use the binary sort algorithm for part (a) and (b)?

If part (b) did not ask you to use the list obtained in (a), could you still use the binary search to obtain Lydia? Or, does the binary search always require a list in order first?

Thanks in advance!

Reply 56

Beat

10

Does anyone else think that cascade charts/scheduling diagrams are worth more than 4 marks? Literally it takes me 10-15 minutes to draw them!

Reply 57

tiny hobbit

15

Original post by Glavien

For question 4 of the June 2013 R paper, how come you need to rearrange the list in order to use the binary sort algorithm for part (a) and (b)?

If part (b) did not ask you to use the list obtained in (a), could you still use the binary search to obtain Lydia? Or, does the binary search always require a list in order first?

Thanks in advance!

Yes your list must be in order before you use a binary search.

Think about it: if you can only look at one letter at a time (which is what the binary search is doing), how would you know whether H is before or after the middle letter in this list?
c y u p w h t a g

Reply 58

Glavien

11

Original post by tiny hobbit

Yes your list must be in order before you use a binary search.

Think about it: if you can only look at one letter at a time (which is what the binary search is doing), how would you know whether H is before or after the middle letter in this list?
c y u p w h t a g

So, for c y u p w h t a g wouldn't you just choose w as your middle letter and discard c-w as h is to the right of w, then carry on the algorithm. I'm guessing that is incorrect because the list is not in order, but it still works right?