can any1 work out these 2 Q's from HSC2003 g.maths? (1 Viewer)

[NiKiTa]

Below I have re-written questions 19 & 20 from Section I (multiple choice) of the 2003 HSC General Maths Exam Paper:
Click here to see the Board of Studies HSC 2003 General Mathematics Exam Paper

The roof of the Sydney Opera House is covered with 1.056 million tiles. If each tile
covers 175 cm2, what area is covered by the tiles?
(A) 184.8 m2
(B) 18 480 m2
(C) 184 800 m2
(D) 1 848 000 m2

Answer: B (i keep getting D)

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Iliana buys several items at the supermarket. The docket for her purchases is shown.

XYZ Supermarket
Milk $ 1.19
* Pepsi $ 1.29
* Disinfectant $ 7.23
* Tea Tree oil $ 4.13
Spinach $ 1.64
Soup $ 1.57

Total $17.05

10% GST INCLUDED IN
COST OF TAXABLE ITEMS
* = TAXABLE ITEMS

What is the amount of GST included in the total?
(A) $1.15
(B) $1.27
(C) $1.55
(D) $1.71

Answer: A (i keep getting B)

If anyone can figure these out - which i'm sure you can please let me know
thanx

 

[cj_bridle]

for the first one when converting from cm2 to m2 remember that 1m2 = 10,000cm2

thus, 1,056,000 x 175cm2 is how many cm2 there are...

then u have to divide that answer by 10,000 to get it to m2 (you were only dividing it by 100 but its m2 remember)

 

[NiKiTa]

ooooh (duh!) is all i can say...
thank you for that cj bridle.
i just know im gonna make a lot of silly mistakes like that in the trials/HSC...

now, does anyone know how to do the 2nd question. the 1st one was just a continuous stupid mistake-- but this one i just can't see what i'm doing wrong.

 

[cj_bridle]

okay, i got A: this is how i did it...

you know that GST is 10% ..

so on the 3 items that have gst included. its 100% (the original price) + 10% (GST) . Thus, the price they give you is equal to 110%

So just divide the first item with the * by 11 to get the 10% GST.. then do the same to the other 2 items... then add the answers together. (best done by storing the answers on your calculator rather than rounding off)

u okay now?

 

[NiKiTa]

yeah thanx again
the thing is - wen someone explains something like that to me i get it
the trouble comes when i have to answer it myself in an exam
i just have to remember these hints - b/c i couldn't answer Q's like that without them.
especially finance maths - i understand it wen its being explained but i tend to get the trickier questions wrong in exams - and there arent any 2nd goes in the hsc...

 

[cj_bridle]

practice makes perfect

 

[NiKiTa]

pobody's nerfect

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do i know what rhetorical means? - homer

me fail english? that's unpossible - ralph

 

[Agnes2810]

uhhh.. i htink i left that question out...

 

[Cape]

I can't remember what i did ... it was so long ago. I know i completelty screwed up my mulitple choice ... i only got like 10 right ... but i so how managed to get 80 for the hsc exam. I don't know what the hell i did.

All i can say is practice.

 

[moe12345]

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Iliana buys several items at the supermarket. The docket for her purchases is shown.

XYZ Supermarket
Milk $ 1.19
* Pepsi $ 1.29
* Disinfectant $ 7.23
* Tea Tree oil $ 4.13
Spinach $ 1.64
Soup $ 1.57

Total $17.05

10% GST INCLUDED IN
COST OF TAXABLE ITEMS
* = TAXABLE ITEMS

What is the amount of GST included in the total?
(A) $1.15
(B) $1.27
(C) $1.55
(D) $1.71

the answer is (A) ok, first u add all the gst items and then u get 12.75 which u divide by 110 which gives u 0.115 then times by 10 which gives u the answer $1.15