Standard Math Q+A Thread

[Lachlan Morley]

Anyone know how to asess CSSA General Maths trial papers

[RuiAce]

Anyone know how to asess CSSA General Maths trial papers

CSSA papers are copyrighted and legal distribution of it is not permitted. It is also therefore not on the forums.

[vanessa mbogo]

please help
what amount must be invested now at 4% per annum ,compounded quarterly ,so that in five years it will have grown to $60000

[RuiAce]

please help
what amount must be invested now at 4% per annum ,compounded quarterly ,so that in five years it will have grown to $60000

Divide by that power and plug into the calculator.

[Potatohater]

Hey! This is the index law for multiplication, remember:



The constants will be multiplied together separately, and then we use the index law above for the pro-numeral:



Does this make sense?

Yes that makes sense, thanks

[Turtlebae]

I don't know what is a stamp duty is can someone please help me on answering question I) & ii)

a) Lisa buys a car which has a market value of $60 000 before on-road costs. Stamp duty on the car is calculated at these rates:

• 3% of the market value to and including $45 000
• 5% of the market value over $45 000

I) calculate the stamp duty payable on the purchase of the car

ii) The car depreciates at a rate of 4.5% pa.  what's is the value of the car 3 years after Lisa buys it?

[jakesilove]

I don't know what is a stamp duty is can someone please help me on answering question I) & ii)

a) Lisa buys a car which has a market value of $60 000 before on-road costs. Stamp duty on the car is calculated at these rates:

• 3% of the market value to and including $45 000
• 5% of the market value over $45 000

I) calculate the stamp duty payable on the purchase of the car

ii) The car depreciates at a rate of 4.5% pa.  what's is the value of the car 3 years after Lisa buys it?

Hey! You can imagine that stamp duty is a sort of 'tax' on goods. So, let's calculate it!

We know that stamp duty is calculated at 3% up to and including $45,000, and 5% after that. So, the first $45,000 of the car will be taxed like this:



Now, the car's total cost was $60,000. So, the 'rest' of the car will be taxed ABOVE the lower rate; ie. at 5%. We've already taxed the first $45,000, leaving us with the last $15,000



So, the TOTAL tax will be



Now, the car depreciates at a rate of 4.5% pa. So, after the first year, the value goes DOWN by 4.5%



After the second year, the car goes down ANOTHER 4.5%. So, we multiply the already depreciated value again!



And, then again for a third year!



There's our answer! Hope that made sense

[Turtlebae]

 

Hey! You can imagine that stamp duty is a sort of 'tax' on goods. So, let's calculate it!

We know that stamp duty is calculated at 3% up to and including $45,000, and 5% after that. So, the first $45,000 of the car will be taxed like this:



Now, the car's total cost was $60,000. So, the 'rest' of the car will be taxed ABOVE the lower rate; ie. at 5%. We've already taxed the first $45,000, leaving us with the last $15,000



So, the TOTAL tax will be



Now, the car depreciates at a rate of 4.5% pa. So, after the first year, the value goes DOWN by 4.5%



After the second year, the car goes down ANOTHER 4.5%. So, we multiply the already depreciated value again!



And, then again for a third year!



There's our answer! Hope that made sense

Thank you so much! And yep I understand it now

[vanessa mbogo]

Zina opened an account to save for a new car. Six months after opening the account ,she made her first deposit of$ $ 1200 and continued depositing $1200 at the end of each six months period. interest was paid 3% per annum, compounded half yearly . How much was in Zina's account two years after first opening it

please help

[jamonwindeyer]

Zina opened an account to save for a new car. Six months after opening the account ,she made her first deposit of$ $ 1200 and continued depositing $1200 at the end of each six months period. interest was paid 3% per annum, compounded half yearly . How much was in Zina's account two years after first opening it

please help

Hey! This question is from the 2013 HSC Paper, and it is based on a formula on the old reference sheet that you no longer receive. This sort of question is no longer assessable, you don't need to know how to do it!

[Potatohater]

What is interpolation and extrapolation?

[RuiAce]

What is interpolation and extrapolation?

When you have a set of data, you may plot it on a graph and then sketch a line of best fit through it. An interpolation is when you use the line of best fit, to draw conclusion of something within the range of data.

E.g. Suppose you plotted weights (masses) on the x-axis, and heights on the y-axis. Suppose your weights range from 50kg to 80kg. You can then use your line of best fit to estimate what would be their height.

An extrapolation is functionally identical to an interpolation, but differs in that the actual value you're using is now outside the range of your data. In the above example, suppose your data still ranged from 50kg-80kg, but you wanted to approximate the height of a person who weighs 95kg. You would then have to extend your line of best fit far enough (this is the extrapolation) so that it allows you to perform this approximation.

(In practice, interpolation is generally quite safe if you know what you're doing, but there can be great risks involved when performing an extrapolation. Extending a line of best fit is not always optimal.)

[emilybrooks99]

Could someone walk me through how to get the answers to the following questions.

1)

2)

3)

4)

5)

Thank you!!

[RuiAce]

Could someone walk me through how to get the answers to the following questions.

1) (Image removed from quote.)

2) (Image removed from quote.)

3) (Image removed from quote.)

4) (Image removed from quote.)

5) (Image removed from quote.)

Thank you!!

It is very off-putting when a ton of questions are thrown at once. In the future, please consider posting lesser amounts, and asking the rest once those have been answered.


_________________________

_________________________

[Aaron12038488]

3. i think this is right, i dont do general math.
so we use the formula A= P(1+r)^n
so we know p is 5000
to find r, we do 8/100 / 12 = 0.06666....
to find n, 12x3 = 36
plug it in the formula u will get D
Note: I'm not sure if this is right, so yh.