VCE General & Further Maths Question Thread!

[RazzMeTazz]

Thanks so much for the detailed explanation MightyBeh!

Thanks StupidProdigy!

[TheMereCat]

Pretty much you rearrange the objective function until you have an equation in terms of y. Then using your ruler (this is why this technique is rarely use as it can be inaccurate), you slide your ruler across the feasible region (with it angled according to the equation you found), where the last point your ruler touches is the max/min value. For maximising, you begin sliding ruler from bottom left corner to top right, for minimising you start sliding ruler from top right to bottom left... does that make sense??

Wow lol, that method spells human error all over it,

Do you ever recommend using this method? Ever?

[Peanut Butter]

Wow lol, that method spells human error all over it,

Do you ever recommend using this method? Ever?

Yes. For (usually multiple choice) questions that don't give any values.

This type of question came up on one of the company papers I have done, and my teacher said the only way to solve it was to use the sliding line technique.

[TheMereCat]

Yes. For (usually multiple choice) questions that don't give any values.

This type of question came up on one of the company papers I have done, and my teacher said the only way to solve it was to use the sliding line technique.

Strange, i've never encountered a question where i was required to use this technique.

[Peanut Butter]

Strange, i've never encountered a question where i was required to use this technique.

It was mentioned in a VCAA examiners report....

So I would highly recommend learning how to do it. It is only unreliable when the data points are close together, otherwise it's a great way to proof-read your linear programming questions.

[Math_lord]

PLEASE HELP!!

-A data set of 8 values has the following characteristics
Mode=41
Mean=32
Median=37.5
Range=32

One of the data set values is 36
Complete the data values in ascending order

17(already gven in the question),___,_____,_____,_____,_____,_____,_____

[BakedDwarf]

PLEASE HELP!!

-A data set of 8 values has the following characteristics
Mode=41
Mean=32
Median=37.5
Range=32

One of the data set values is 36
Complete the data values in ascending order

17(already gven in the question),___,_____,_____,_____,_____,_____,_____

17, 29, 36, 37, 38, 41, 41, 49

Is this correct? I'll provide an explanation if it is.

[@#035;3]

Nope... The mean is 32.

[StupidProdigy]

PLEASE HELP!!

-A data set of 8 values has the following characteristics
Mode=41
Mean=32
Median=37.5
Range=32

One of the data set values is 36
Complete the data values in ascending order

17(already gven in the question),___,_____,_____,_____,_____,_____,_____

I don't think the question works..maybe I'm missing something. I got to (17,a,b,36,39,41,41,49). Must be two 41's for it to be the mode, must have 39 to get a median of 37.5. Got the 49 from the range instruction. So that left me with a and b, which cannot give a sum and be numbers less than 17 and fit the instruction that the mean=32
edit: not the only one with this problem which is a relief, the question is wrong I'd say.

[BakedDwarf]

I don't think the question works..maybe I'm missing something. I got to (17,a,b,36,39,41,41,49). Must be two 41's for it to be the mode, must have 39 to get a median of 37.5. Got the 49 from the range instruction. So that left me with a and b, which cannot give a sum and be numbers less than 17 and fit the instruction that the mean=32
edit: not the only one with this problem which is a relief, the question is wrong I'd say.

When i did the question again, that is what i also got.
a + b = 33
This is impossible without one of them being lower than 17
Hence, i don't think there is a solution to this problem

[plato]

It was mentioned in a VCAA examiners report....

So I would highly recommend learning how to do it. It is only unreliable when the data points are close together, otherwise it's a great way to proof-read your linear programming questions.

The sliding line method is best done by calculation rather than sliding a ruler. If you compare the calculated gradient of the objective function with the caculated gradients of the constraints, you can see which lines are steeper in comparison with others. It can then be easy to imagine sliding the objective function to its limit.
The sliding line method is not stipulated in the 2015 study design and so cannot be examined in 2015. However, it is written in the new study design starting in 2016 and so will be fair game from next year.

[BakedDwarf]

This question is for the Networks module.

When we have a loop in a network, does it count as a 1 or 2 in the adjacent matrix?
For example, for the network diagram below, which matrix is the correct one? (i don't know how to use the fancy tools to make an actual matrix)
      [0  1  1  1 0]                          [0  1  1  1  0]
      |1  0  1  2  0|                         |1  0  1  2   0|
A= |1  1  0  0  1|        OR       B= |1  1  0  0  1|
      |1  2  0  0  1|                         |1  2  0  0  1| 
      [0  1  1  1  1]                         [0  1  1  1  2]   

Maths quest says that A is correct,  but a neap exam says B is correct

[TheAspiringDoc]

Must be two 41's for it to be the mode

Perhaps this is where everyone is going wrong? What if the were, say, three 41s?

[Math_lord]

Hey guys,
Thanks so much for all helping out !
In the end, after so many possibilities, i have come to a final conclusion...THIS QUESTION IS WRONG

REASON: Because since the mean is 32 and there are 8 numbers(32*8=256) we should be getting a total of 256 when the numbers are added up, which clearly doesn't seem to occur.

[TheAspiringDoc]

Hey guys,
Thanks so much for all helping out !
In the end, after so many possibilities, i have come to a final conclusion...THIS QUESTION IS WRONG

REASON: Because since the mean is 32 and there are 8 numbers(32*8=256) we should be getting a total of 256 when the numbers are added up, which clearly doesn't seem to occur.

Yes, but the whole question pretty much revolves around the "clearly doesn't seem to occur" bit, so that's not areally a valid reason?