AQA D2 Unofficial mark scheme

Original post by Bobjim12

Felt pretty good about my answers, discuss yours too:

1.

a. 58 hours
b. CGIKL
C. Float time = 2
d. 60 hours worker 1: critical path 2: everything else

2. 61

3. Define zero-sum game

Monica plays C Vladimir plays ?

B dominates C

play A with p = 0.6, C with 0.4

Play D with 0.9, E 0.1 F 0

4. 3 as 8 < 20 and 15

Max P = 36, x = 6, y = 0, z = 6, s = 8?, t = 0, u = 0

5

DBCA

£28100

6.

X = 45?

Max flow = 32

Hope these are all right.

I agree with all of them apart from 60, I got 61

Reply 2

OP

Original post by Jm098

I agree with all of them apart from 60, I got 61

I wasn't sure about that one tbh, what was your working?

Reply 3

Dapperblook22

8

That was a lovely D2 exam overall I think, and a nice end to the exam season :biggrin:

Most of your answers I can remember getting, so pretty confident overall - probably dropped 3 marks though.

Reply 4

Original post by Bobjim12

I wasn't sure about that one tbh, what was your working?

I delayed to fit B? then H and I, but as F has float time of 2 so I only needed to be delayed by 3 days

Reply 5

OP

Original post by Dapperblook22

That was a lovely D2 exam overall I think, and a nice end to the exam season :biggrin:

Most of your answers I can remember getting, so pretty confident overall - probably dropped 3 marks though.

It was quite a nice paper, i felt though that i was gonna run out of time as i just finished 4 with about 25 minutes to go. Thank God that i didn't make any mistakes while rushing the last question. The extra flow table scared me a little bit; there were like 8 blocks but i could only find 3 flows!

Reply 6

OP

Original post by Jm098

I delayed to fit B? then H and I, but as F has float time of 2 so I only needed to be delayed by 3 days

I saw that E and B needed to be moved. After moving these, B was over the end of J by two hours, hence 60, but i feel as though you might be right with using F's float time

Reply 7

Yuoopwe55

I got the exact same answers, for every question, I'm so happy :biggrin:

Reply 8

Dapperblook22

8

Original post by Bobjim12

It was quite a nice paper, i felt though that i was gonna run out of time as i just finished 4 with about 25 minutes to go. Thank God that i didn't make any mistakes while rushing the last question. The extra flow table scared me a little bit; there were like 8 blocks but i could only find 3 flows!

Yeah, there were too many blocks :tongue:

, I got four flows of 1 though, so a total augment of 4 overall (there was also two flows of 1 and one of 2 as an alternative) to give a max flow of 32.

Reply 9

OP

Original post by Dapperblook22

Yeah, there were too many blocks :tongue:

, I got four flows of 1 though, so a total augment of 4 overall (there was also two flows of 1 and one of 2 as an alternative) to give a max flow of 32.

Oh yes, i had 1 2 and 1 flows. Excellent. I may have just scraped 100 in this one! Quite convenient after the shambles that was M3

Reply 10

What has it been for full UMS? Like 73?

Reply 11

Could you do the network flows in pencil as well? Haha

Reply 12

OP

Original post by Jm098

What has it been for full UMS? Like 73?

Its been like 73/74 most years

Reply 13

Char_Bra

For the simplex question, did people get fractions as their final values for P etc? I did and just wrote them to 3 dp.... Is this right?

Reply 14

Dapperblook22

8

Original post by Jm098

Could you do the network flows in pencil as well? Haha

Yes and no (kinda); in reports they recommended doing the initial flow in pen so it is clearer to the examiner to see and then augmenting the flows with pencil.

Reply 15

Original post by Dapperblook22

Yes and no (kinda); in reports they recommended doing the initial flow in pen so it is clearer to the examiner to see and then augmenting the flows with pencil.

Oh really

did it all in pencil

Reply 16

Rabadon

11

Not sure 1d is correct because of you assign one worker critical path and the other everything else you end up starting I before you've finished its presendence(E) and so it doesn't work

Reply 17

tanyapotter

was it monica C and vladmir D for their play-safe strategies?

also, did we have to state the minimum completion time?! I didn't - i just left it in the diagram :frown:

Reply 18

tanyapotter