Quantitative Methods III (QM3 for IBE/INF)

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I keep getting questions related to when optimal solution and objective value increase/decreases/stays the same wrong! any help please?
I keep finding 13 for the EFT is that normal?
Can someone explain how they find the objective function please?
Its quite simple, So you have the selling price per mix and the price for the ingredients. So for each one lets say P1 you do the selling price on mix 1 - the cost of peanuts per ton so 900-600=300P1 then 1050-600 for P2 and 950-600 for P3 and so on. In the end you also have the binary variables which are either 0 or 1.
How do we know that the allowable increase is 2?
how do we solve these type of questions?
its explained quite nicely at the end of chapter 6.
For activity 6 is EST 11 and EFT 14? The answer key says that EST is 9??
yeah there are a lot of mistakes in the answers... dont worry about it
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5-3 is not correct because constraint 5 is not satisfied
I uploaded the correct/updated document now, thanks for letting me know!
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this is version E
Advice on how to pass this exam please!!
same with every QM exam, have a look at the reader and do the exercises in it, go to the tutorials and ask questions for the stuff you couldn't do and do the old exams for 2 full days before the exam and you will 100% pass.
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remember that if we are talking about binary variables constraints must be =< 0 otherwise they take values that do not exist outside of the domain
guys i need help with this can we start posting in this bi
How? I thought it was C
Why is it part of the optimal solution?
RHS=LHS of the inflow-ourflow=demand-supply standard flowconstraint
Can somebody explain why the answer for question 2 is d?
From the constraint in ex1 (at least 40% nitrogen)
Q25 - Do you just add another warehouse?
For 3, the correct answer is D. Does someone have an explanation for this?
Because R1 and R2 indicate what you need to buy as supply this should be at least as much as the optimal output requires
For 8, the correct answer is D. Where do these numbers come from?
see question 8 in the picture
Q14: can someone explain constraint a?
Because on Monday demand is 2 so for all available "spots" for Monday need to be equal to 2
Can someone explain the answers for question 4 and 6 in the old exam questions for Chp 2 in the reader?
Q4 - ? Q6: The maximum amount of water available is 5000 m3 , therefore the total usage of water cannot exceed 5000 --> total usage of water <= 5000. The total usage of water can be written as the total usage of water for hyacinths + total usage of water for tullips This is: 5 HL +5 HA + 4 TL + 4 TA Therefore, 5 HL +5 HA + 4 TL + 4 TA <= 5000
Can someone explain how to solve question 5? The answer is apparently: The optimal solution remains unchanged, and the objective value remains the same. Isn't the following answer also right?: It is now less profitable to produce Tables, since they are more expensive to produce now.
Cus I think the sensitivity report is wrong. Constraint RHS for Iron is shown to be 1000, whereas the texts earlier describing the case mentions 1200. This would naturally give two different slacks..
Will there be an answer key?
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He just posted it its announced on studentportal!
Is 13 still wrong?
For what all questions are you guys sending in complaints?
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question 26-28 are the wrong answers, no?
I just wrote a comment about it to the cc, they made a mistake with respect to activity 6 in my opinion.
Someone please tell me they are wrong :’)
Can somesone explain why question 12 is "Increasing the number of required labourers in month 3 with at most 40 will not change the optimal solution, nor its value."
allowable increase explain it
question 2: why is this c?
because you need a+b+c.
How do you solve this question ?
the feasible region is increased, so more feasible options. this means that the optimal value will increase (because its a maximzing problem) or it will stay the same. we don't have enough information to know for sure which one will happen
the answer in the 25 is c. Why is it part of the optimal solution?
How do you find the coefficients?
(189- 136)H + (149-101)F + ( 129-96)S etc...
WHERE DOES THE 0.05 COME FROM?
Notice how the inflow of each node, in this case L + B1 + 0.25 (the 25,000 the task mentions the company already has in month 1) has to be higher or equal to the outflow, which is C2 + a constant equal to the difference between Accounts Receivables and Required Payments which for month 1 would be 30,000 or 0.3 (1.8 - 1.5). So: L+B1+0.25 >= C2 + 0.3 rewriting it in standard form then gets you the 0.05 on the RHS: L+B1-C2 >= 0.05 Edit: the 25,000 also could be seen as C1 which the task mentions is a constant
why is it B?
just put numbers in and read the question... So in short 1-1-0=0 so it satisfies the condition and then 0-1-1 =-2 also satisfies the condition.
I heard that the coordinator is going to make the exam harder this year, did he gave any additional information regarding the changes that he will apply? Is the exam going to be similar to last year's exam?
The only thing he said in the lecture was how there where 7 people who failed last year and that he expects 15 this year but he laughed about it. Also this year will have sensitivity reports so it might be easier.
Why is the buying price always more expensive than selling price? is there a mistake in the question?
How do you find the answer A ?
How do we get 0.5, 0.5 and 0.25 in B?
i had the same issue should be 0.25 0.25 and 0.33
converting every minutes into hour, there is a mistake
Can anyone explain what do they intend by optimal solution and optimal value? Which of the two corresponds to the optimal coordinates?
Optimal solution = Optimal coordination. Optimal value = Optimal value of the objective function :)
How do you solve this?
How do you know this? In the answer sheet it says because the shadow price is negative.. where can we see this?
How do we know allowable increase range?
you cant solve this one i asked my tutor and she said no way you can solve this
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How did u know where to put the 1's in the constraints..?
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For exercise 6.3 constraint 12, shouldn't the RHS side be 5 since it takes 5 weeks to complete activity 8. So S10>=S8+5-R8?
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Could someone explain why the answer to question 13 is C ?
I believe that this is because answer C is implicitly linked to the decision of which plant to build (I,e. XS and XB) Thus their coefficient can be their capacity, and if XS=1 then that is the amount by which the production will increase... Or something along those lines. make sense?
Is it normal that all the exams don't have the sensitivity reports ? We should have them but the exams from the student portal don't include them
i asked the same question in class and our tutor said you have to get thm (wher idk) otherwise we can't solve the questions.
Is it just me or are other's also realising that the chap exercises are not really representative of the exam questions? I get that they are meant to help us understand the material but still..
Any advice on whats the best way to prepare for the exam? or understanding the concepts?
Can anyone solve question 2? P.55
In the text is mentioned that fertiliser 1 must contain 40% of nitrogen (N1). In option D; 3000/(3000+5000+2000) = 30%. The constraint is therefore not met, hence D is the right answer. All other options are feasible.
Aah damn, that makes a lot of sense! Thanks for taking the time to answer, much appreciated :)
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I think whole process is correct beside the fact that the last three constraint should be equal and not more or equal. Does it make sense to buy candies that cost 165 with 175? also stated that machine do not return any change
It's not possible to buy everything with equal amounts. And otherwise you wouldn't get to the right solution.
Which solution refers to exam version C?
left one
Why is it c ?