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HSC General Maths Marathon (2 Viewers)

rednellav

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Actually having difficulties with a ridiculously easy question in 07. I keep getting $427.5 which is wrong.

Anyone mind having a look?

 

DJ696

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Actually having difficulties with a ridiculously easy question in 07. I keep getting $427.5 which is wrong.

Anyone mind having a look?

100 Australian dollars = 75 US Dollars meaning 150 us dollars = 200 Australian dollars.
Equal 800 australian dollars to convert to euros.
100 Australian dollars = 60 euros.
So, 60 x 8 = $480.
She has $480 to spend in Europe.
 

rednellav

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100 Australian dollars = 75 US Dollars meaning 150 us dollars = 200 Australian dollars.
Equal 800 australian dollars to convert to euros.
100 Australian dollars = 60 euros.
So, 60 x 8 = $480.
She has $480 to spend in Europe.
Yeah cheers. I went the wrong way with the USD.

Think I have to work on my setting out so I don't confuse myself like fuck.
 

john-luke

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Can anyone explain variation and inverse variation to me? Im generally hopeless when it comes to equations formulating my own equations. Any help is greatly appreciated.
 

rednellav

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Can anyone explain variation and inverse variation to me? Im generally hopeless when it comes to equations formulating my own equations. Any help is greatly appreciated.
It's just algebra to find the missing "link" (k) to given equations, where k is the constant value.

Direct variation is simply y = k*x

Inverse is y = k/x

They'll always give you the values y and x first so you have to solve for constant k, then give you x in another question and you'll have to solve for y using k (the value you just figured out) and x.

Can't think of any examples so bare with me, but: the number of balls in a bag is directly proportional to how much the bag has stretched

if there are 100 balls in the bag and the bag is stretched 10 units find the constant k

100 = k * 10

therefore k = 10

now, how many balls are in the bag if the bag is stretched 50 units

well we know the constant now, so y(number of balls) = 10 * 50

= 500 balls

idfk if that example even works but i'm tired as fuk hopefully that helps a bit
 
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jess_1495

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Anyone have an easy way to remember when to use the future value formula and when to use the present value formula????
 

john-luke

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Thanks mate, Legend! i have this tendency to overcomplicate simple things. Always do well on the hard stuff though
 

Drifting95

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Any help with this? I looked at the sample response but i don't understand the reason for the working...

[/URL][/IMG]

[/URL][/IMG]
 

rednellav

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you can break it up into a rectangle and 2 triangles bruh

other than that, I don't understand those ratio questions either fuark
 

DJ696

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Any help with this? I looked at the sample response but i don't understand the reason for the working...

[/URL][/IMG]

[/URL][/IMG]
The ratio of heights is converted by times it 10 as the scale factor is hard to distinguish in decimals.
The ratio 8:3 of the 4m:1.5m :)
The ratio d + 3 / d = 3/8 is the formula used for scale factor find the sides.
Then the d from the denominator is times to left and right.
From there you substitute to find the value of d involving algebra getting the height of the shadow :)
 

rednellav

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The ratio of heights is converted by times it 10 as the scale factor is hard to distinguish in decimals.
The ratio 8:3 of the 4m:1.5m :)
The ratio d + 3 / d = 3/8 is the formula used for scale factor find the sides.
Then the d from the denominator is times to left and right.
From there you substitute to find the value of d involving algebra getting the height of the shadow :)
thats actually kinda cool how the maths works itself out if you follow the rules

just got 22/22 in 2009 paper multiple choice zomg finally no stupid mistakes
 

DJ696

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thats actually kinda cool how the maths works itself out if you follow the rules

just got 22/22 in 2009 paper multiple choice zomg finally no stupid mistakes
MC keeps screwing me over :( haha! but you all set for tomorrow? plan to attack the paper?
 

Drifting95

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The ratio of heights is converted by times it 10 as the scale factor is hard to distinguish in decimals.
The ratio 8:3 of the 4m:1.5m :)
The ratio d + 3 / d = 3/8 is the formula used for scale factor find the sides.
Then the d from the denominator is times to left and right.
From there you substitute to find the value of d involving algebra getting the height of the shadow :)
What formula? :blink2:

Thanks for the help
 

rednellav

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haha, what past paper you doing or just doing multiple choice?
2009. Done about 7 past papers now (should have done all of them but ran out of time towards the end). Might sneak in one tomorrow and that'll be that. Going fairly well though.

Only thing in this damn subject is reading the questions properly. They may as well call the subject "Advanced comprehension and basic maths" or something.
 

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