Answers to General Maths Exam (1 Viewer)

berra

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this paper was hard man!!! compared 2 last years 1, it was 50556321+6789 times harder....
does anyone agree?

also, all the exams i have done up 2 date have been much harder than that of last year!!!

anyone agree? im starting 2 get worried...
but does this mean that regardless of marks, theyd scale us according 2 the state? like obviously many ppl didnt go good, so does it mean, the higher our marks (standard dev), the more we'd get scaled???

anyone know?
 

gamblor247

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lol whooooohoo, im not the only one that stuffed up! shit it was bloody hard, last yeears paper was a walk in the park! but i guess if every1 stuffed up theyll rank us up??well i hope! i ended up first n i think i got around 70 in this exam!
btw didmartha have a better investment?i was pritty confident with that?but i guess u guys are smarter?
peace out!!!!
 

berra

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like no offence, but ther r so many incorrect answers there... ur just demotivating people 4 no reason... btw, i hav d whole exam paper sitting infront of me... n i re-did it all


PC said:
Hi everyone,

These are just the answers. I'll to post worked solutions later. Sorry for the delay. There's now a rule which says that teachers can get the papers 2 hours after starting. Last year it was 30 minutes.

Anyway ... for the record ...

Section I
1. A
2. D
3. B
4. C
5. B
6. B
7. D
8. C
9. C
10. C
11. A
12. B
13. D
14. A
15. A
16. C
17. D
18. D
19. B
20. C
21. B
22. B

Section II
Question 23
(a) 4ab/3 i dont noe bout this one, but rnt we meant 2 make the denominators the same, which will give = 3a6^3/3bw X 4w^2/3bw = 12ab^3w^2 ??? because denominator cancels out since theyr the same...

(b) (i) 19*C
(ii) February
(iii) August its asking in monthS = so its from may to september
(c) (i) Systematic sample, something like every 5th student in order on the roll. it can also b stratified
(ii) Mean is 7.275 hours per week (using class centres). Mean class is 5-9 hours per week.
(d) (i) $6
(ii) 4 kg or 7 kg
(iii) Weights more that 4 kg, up to and including 6 kg, and weights more than 7 kg.
(iv) $1.50 per kg

Question 24
(a) Vertical axis does not start at 0, pictures change in three dimensions instead of just one. also, scale of boxes are inacccurate = creates bias
(b) (i) 71* its 70*
(ii) 109 cm
(c) Lovely box plot, Min = 140, Q1 = 145, Median = 150, Q3 = 170, Max = 190
(d) (i) 567 L
(ii) 30 cm this isnt correct. d answer is 15cm... y did u X2? the trough is only d cm long... thats it

Question 25
(a) (i) 6
(ii) 1/3
(iii) 2/3
(b) (i) 28 days
(ii) $8.61
(c) (i) 1/60
(ii) 1/5370
(d) Martha's effective interest rate is 6.36%p.a. so Paul gets the better deal. i actually put them all into an annuity formula (with the same principal) and martha's one was higher, and i also double checked...???

Question 26
(a) (i) Lovely diagram
(ii) 53 m
(b) (i) Lovely net - probably best is to have four lots of a triangle on top of a rectangle next to each other across the page.
(ii) 252 m2
(c) (i) 98
(ii) 43/100 ??....its 74/200 = 37/100
(iii) 28
(d) 17 h 30 min

Question 27
(a) (i) $130 000 over 30 years .. also incorrect... max is $80 000 over 10 years.
(ii) $45964.80
(b) (i) y-intercept exists when height = 0 cm, but this will never occur. No person ever has a height of 0 cm.
(ii) George's feet should be 3 cm longer than Harry's
(iii) For this data, correlation coefficient should be positive rather than negative. Correlation coefficients only range from -1 to 1 so r = -1.2 is not possible.
(c) (i) $24000
(ii) $7593.75
(iii) Graph - Straight line from $30000 to $24000 after 3 years, then curve down to $7593.75 after 7 years

Question 28
(a) (i) 4 combinations: 1 x $2, 1 x 50¢; 2 x $1, 1 x 50¢; 1 x $1, 3 x 50¢; 5 x 50¢
(ii) 6/55
(iii) $(2x + y + 0.5z)
(b) (i) $12
(ii) $17 500 which is 3500 vehicles
(iii) v = 6000 – 500d
(iv) Anne's statement is incorrect. Maximum daily income is $18 000 when the toll is set at $6 per vehicle.
 

uhawww

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^ a number of your "corrections" are wrong. I'm not going to point them all out, but I'll point this one out.

"this isnt correct. d answer is 15cm... y did u X2? the trough is only d cm long... thats it"

You need to double it because the area of an ellipse formula only works on a full ellipse. If you used that to get the answer you would have needed to double the area. The result was 30, which was the semi-b axis, semi meaning half which means 30 was the half length (depth of the tub).
 

berra

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its only half an ellipse.. and d represents that HALF, nothing more...

and im curious, which others r wrong, if u dnt mind me asking
 

uhawww

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Yes it's half an ellipse, but to work out the full area of an ellipse you only use a half legth, which a half length of an ellipse makes the depth of the tub.

The other ones that are wrong (that I know of) are:

"also incorrect... max is $80 000 over 10 years."

and

"i dont noe bout this one, but rnt we meant 2 make the denominators the same, which will give = 3a6^3/3bw X 4w^2/3bw = 12ab^3w^2 ??? because denominator cancels out since theyr the same..." (you were just asking here though)

He has both those correct.
 

hammah

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Ok Berra mate sorry, but you're wrong about the ellipse question - it is 30. I got 15 in the exam too, but the i changed it.

I have a question about the multi choice Q3, is the answer not D .. or did i put the angle of depression in the wrong spot. I put it next to the building, not by the base of the tree.

Also, question 18 is B, not D. You only square root the 49-5t, not the whole side.

Anyone think they would accept Quantitative sampling as an answer for 23c i) ??

24b i) is 70 degrees, it rounds down.

25b i) is 29 days, i put 28 coz i didnt read the bottom in the exam.

25 d) Martha has a better deal - works out to be a higher rate.

26c ii) and iii) boned me...hate probability

27a i) is DEFINATELY not 10 years and $80k....have a look down the table at 30 years and $130,000 buddy


and 28b iii) im pretty sure the question says "in terms of d" - which means the answer is 'd=6000-v/500'
 

PC

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teels said:
question 23 (b) (iii) said months?
Yes, it said months, but it actually said months is, and strictly speaking it should be months are. That's one of many places in this exam where I think the way the question is written can induce some careless errors.
 

PC

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Thanks uhaww and berra for checking, a couple of boo-boos on my part.

That's what I love about this site! Instant feedback!

When I was working through this paper, I started to dislike it very much. There are so many places where students could make silly mistakes, simply cause of the wording of the question.

That table in Q27. Question asks for the maximum amount that Liliana can borrow. And first thing I did too was look for the highest amount under $1000. That's not what the question asks for. The highest amount that Liliana can afford to borrow is $130000.
 

sedated_mind

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could someone who has the exam please scan it or put it up for me coz then i can roughly work out what i got.
 

brycewalker

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Question 25(b)(i) definatley 29 days

Question 26(c)(ii) there are 86 people who are carriers of the virus. 74 of these people had text results which showed this. Therefore the probability is 74/86 = 37/43
 

PC

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sedated_mind said:
could someone who has the exam please scan it or put it up for me coz then i can roughly work out what i got.
It's under copyright, so I don't think it's possible to post the exam up on the site. Go to do the right thing.
 

PC

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brycewalker said:
Question 25(b)(i) definatley 29 days
Yes ... definitely 29 days.


brycewalker said:
Question 26(c)(ii) there are 86 people who are carriers of the virus. 74 of these people had text results which showed this. Therefore the probability is 74/86 = 37/43
The tested group contained 200 people. The results showed 86 people as carriers (12 incorrect results), so P = 86/200 = 43/100.
 

xblizzard

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The bearing question said A from B, not B from A... FUCK FUCK FUCK FUCK :burn: :burn: :burn: :burn: :burn: :burn: :burn: :burn: :burn: :burn: :burn: :burn: :burn: :burn: :burn: :burn: :burn:

Other than that i fucked up a bit, hopefully not heaps
 

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brycewalker said:
Question 26(c)(ii) there are 86 people who are carriers of the virus. 74 of these people had text results which showed this. Therefore the probability is 74/86 = 37/43
What I did was,

74 / (74 + 98)

= 74 / 172

= 37 / 86

because it said;

the person selected from the tested group is a carrier of the virus,

what is the probability that the results would show this.


So the people that tested positive for being a carrier are 74, and the people that tested negative for not being a carrier also were in fact a carrier, because the test result was negative, hence they are not 'not a carrier' but infact a 'carrier'. There were 98 of these people.

So the people that were actually tested as a carrier were 74, over the total amount of the ACTUAL carriers = 74 + 98 = 172.

This question is badly worded as it doesn't state whether the people are tested positive for the disease or positive in being a carrier or non-carrier.
 

DE MAN

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hey guys
i got ranked 28/110 in my year will this help push my marks up as this means i'm ranked 75% in my year:mad1:
 
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PC said:
That table in Q27. Question asks for the maximum amount that Liliana can borrow. And first thing I did too was look for the highest amount under $1000. That's not what the question asks for. The highest amount that Liliana can afford to borrow is $130000.
I don't have the paper, but since her budget was $1000, the answer would be to identify the most she can borrow without spending over $1000, wouldn't it?
 

sedated_mind

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PC said:
It's under copyright, so I don't think it's possible to post the exam up on the site. Go to do the right thing.
damnit, ill have to hunt my old teacher down then
 

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