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# D1 Help PLEASE.. I BEG! (Heineman Book) watch

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1. Ex 5E

The single qs can be found in da book. I start off this qs by trying to make a forward and back scan to use them to find start and finish times. BUT I AM getting minus numbers. Can anyone reply only putting the earliest and latest event times in a table so that i can go on with this qs. thank you.
2. I tried to find my D1 exercise answers, as ive done Chapter 5 all qs... I will keep looking and leave you with the sentiment that chapters 6 and 7 are easier, aside from Simplex, which took 2 whole days of being locked in my room to finally understand... or at least comprehend.

SIMPLEX IS THE DEVIL'S SLUT-*****.

Sorry...
3. Activity Ei Li Ej Lj Float
A 0 0 2 2 0
B 0 0 7 7 0
C 0 1 10 11 1
D 2 2 7 7 0
E 8 7 15 16 1
F 7 7 13 13 0
G 10 11 12 13 1
H 13 131717 0
I 10 14 13 17 4
J 15 16 16 17 1
4. (Original post by lgs98jonee)
Activity Ei Li Ej Lj Float
A 0 0 2 2 0
B 0 0 7 7 0
C 0 1 10 11 1
D 2 2 7 7 0
E 8 7 15 16 1
F 7 7 13 13 0
G 10 11 12 13 1
H 13 131717 0
I 10 14 13 17 4
J 15 16 16 17 1
how did u get all dat.. could u give me an example for one or 2 of the activites?
5. At a quick glance, you can see that the longest route to get to the end is 17 via B F and H. So you can fill in the earliest start and finish times for vertices involving these as they are the critical path. The last activity (H) is going to have 17 and 17 for its earliest and latest finishing times. You can then work backwards from that and fill in the various late start times.
E.g. As H must start at 17 you know that G must start by 11 to give time to finish so that H can be started and completed by 17. And so C must have finished by 11 and have started by 1.
The same thing can be done with F, all activites leading up to F (B and D) must have finished by 7. And E must have finished by 16, so that J can be completed in time.
6. Use the example in the book.
The early time for a vertex is the latest time u can get to that vertex.
The late time is the latest time that activites from that vertex can start.
7. (Original post by Gaz031)
Use the example in the book.
The early time for a vertex is the latest time u can get to that vertex.
The late time is the latest time that activites from that vertex can start.
The early time for a vertex is the latest time u can get to that vertex.

why the latest.. shuldnt it be the earliest?
8. (Original post by ziya_the_king)
The early time for a vertex is the latest time u can get to that vertex.

why the latest.. shuldnt it be the earliest?
The early time of the vertex is the earliest time you can leave it. So the early time for vertax B, is the latest time activity AB can be completed by.

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Updated: December 28, 2004
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