Maths Sc Questions (need some help) (1 Viewer)

[lookoutastroboy]

Hey guys,

These are some questions that I found difficulty with in the maths sc (in no particular order - please provide worked solutions if you can =))

2004 SC Question 70 and 75

2005 SC Question 71, 73, 75 (really need a good explanation for this)

2006 SC Question 49

2001 SC Question 53 (this is the hardest question - i cannot do it!!)

http://www.boardofstudies.nsw.edu.au/schoolcertificate/sc2001/pdf_doc/maths_sctest_01.pdf

http://www.boardofstudies.nsw.edu.au/schoolcertificate/sc2004/pdf_doc/mathematics_sctest_04.pdf

http://www.boardofstudies.nsw.edu.au/schoolcertificate/sc2005/pdf_doc/mathematics_sctest_05.pdf

http://www.boardofstudies.nsw.edu.au/schoolcertificate/sc2006/mathematics_sctest_06.pdf




Thanks in advance guys


Bye,

lookoutastroboy

 

[angelarr]

2004 Qu 70:

(c) $64
If you think about it, it says you can only use two vouchers on a meal of equal or less value, so that means you have to automatically rule out the $24 meal. The 2nd highest meal is $22, which he could use a voucher on, because it costs less than the $24.
So up until now, he's used 1 voucher, and he would have to pay $24 + $11.
He now has one more voucher to use, and it has to be on the $18 meal, because he can not pay $18, and get a discount on the $20 meal because it costs more than the $18.
Hence, altogether he has to be $24 + $11 + $20 + $18 = $64

2005 Qu 71:

You're just going to have to trace along the paths

2005 Qu 73:

(c) 1/3

Let each side of the cube be 2x. The surface area would therefore be (2x)(2x)(6) = 24x^2.

However, once the cube is cut into 2 rectangular prisms, the "width" is no longer 2x, but rather just x as it is cut in half. Therefore, the surface area of one rectangular prism would be (2x)(x)(4) + (2x)(2x)(2) = 16x^2.
Two rectangular prisms = 32x^2.

Increase in surface area: 32x^2 - 24x^2 = 8x^2, which is a third of the original SA

2006 Qu 49:

(B) 80cm x 40cm

I think the problem with this question is deciphering what exactly they're trying to ask. They are trying to ask for what values will the distance between the centre panel and the width, and the distance between the centre panel and length is the same.

So 120 - ____ = 80 - _____
So you try all the answers out, and you find that only b works as
120 - 80 = 40, and 80 - 40 = 40

2001 Qu 53:

(b) 3 x 5 x 4

The dimensions of tjhe big prism is 9 x 15 x 28

Therefore you need dimensions which are multiples of all the numbers, and the only choice is 3, which goes into 9, 5 going into 15, and 4 into 28.

Hope I've been helpful!

 

[salih08]

2004 SC Q 70-
70 Ervino took his family for dinner. The cost of each meal was: Ervino, $24;
Chris, $18; Rebecca, $20; and Ben, $22. Ervino paid the total bill, using two of
these discount vouchers: Buy any main meal and
receive a second main meal
for price (up to equal value) half price

What is the lowest total amount he could be required to pay?
(A) $61 (B) $62 (C) $64 (D) $65

the answer is c because for the lowest he would use the half price voucher on the highest possible price. but since its up to and including he cannot but a cheaper main meal and getting a more expensive one half price. so first he would pay 24 for ervno, then half price for the next highest (the higher the price the higher half of it thus the higher u save) which is 22 that becomes 11.

so far 24+11 = 35

now there is a $20 and $18 left with 1 more voucher. again u can only use the voucher for the lower price since its up to and including. so 20+ half of 18 = 29.
29+35=64 - C

 

[lookoutastroboy]

thanks so much!!!! good luck for your sc 2moro - hope u get band 6s