Standard Math Q+A Thread

[Aayamstha7]

Hey, i did all the working out to find out 113cm (cubed) (volume of the sphere), unfortunately i overthought it and tried to minus the hemispshere in the cone. how many marks could i expect to lose?

[erhulloollie]

Hey, i did all the working out to find out 113cm (cubed) (volume of the sphere), unfortunately i overthought it and tried to minus the hemispshere in the cone. how many marks could i expect to lose?

I'm not totally sure... it depends on the marking criteria!
It was a 3 mark question from memory so you would probably still get 2/3

[jamonwindeyer]

We've got an exam discussion going for you guys, see here!

[PrincePringle]

me too!! thanks

[Lumenoria]

Hi, I'm doing a question;
For a reducing balance loan of 180000 at 9% over 12 yrs, with fortnightly repayments of 932.75, find;
a. Total interest payable
b. The equivalent flat rate of interest annually
I was wondering if theres a method to calculate total interest payable (for a) without manually drawing out the whole table? In this case, you would have to draw 312 rows (12x26 fortnights) and I swear that's not the most efficient way, but the textbook doesnt mention anything otherwise.

And I'm just at a complete loss as to how you would do b

[huss1235]

Hi, I'm doing a question;
For a reducing balance loan of 180000 at 9% over 12 yrs, with fortnightly repayments of 932.75, find;
a. Total interest payable
b. The equivalent flat rate of interest annually
I was wondering if theres a method to calculate total interest payable (for a) without manually drawing out the whole table? In this case, you would have to draw 312 rows (12x26 fortnights) and I swear that's not the most efficient way, but the textbook doesnt mention anything otherwise.

And I'm just at a complete loss as to how you would do b

Hi okay this is how i would do the question    *= multiply  /=divide
a) 932.75*26=24251.5 that is per year as there is 26 fortnights now for 12 years you do 24251.5*12=291018
now 291018-180000=111018 which is the total interest payable
b) okay so for this question begin with the simple interest formula which is I=PRN
now to find I( intrest  ) you make it the subject of the formula which is r= I/P*N
now the interest is total repayable - the principle which is 291018-180000= 111018 therefore the answer will be
111018/ 180000(the principle)*12 years = answer* 100
which is 5.14% to 2dp
if you dont understand or need anything feel free to ask
thanks

[jamonwindeyer]

Hi, I'm doing a question;
For a reducing balance loan of 180000 at 9% over 12 yrs, with fortnightly repayments of 932.75, find;
a. Total interest payable
b. The equivalent flat rate of interest annually
I was wondering if theres a method to calculate total interest payable (for a) without manually drawing out the whole table? In this case, you would have to draw 312 rows (12x26 fortnights) and I swear that's not the most efficient way, but the textbook doesnt mention anything otherwise.

And I'm just at a complete loss as to how you would do b

Hey! Just clarifying on Huss' answer above:

- For (a), you need to subtract the principal from that final answer to get interest payable. So the answer to (a) is actually that number $111,018
- And just clarifying for (b), it is \(R\) you are making the subject of the formula, which is:



Substituting those values as Huss has shown you will get you the answer

[huss1235]

Hey! Just clarifying on Huss' answer above:

- For (a), you need to subtract the principal from that final answer to get interest payable. So the answer to (a) is actually that number $111,018
- And just clarifying for (b), it is \(R\) you are making the subject of the formula, which is:



Substituting those values as Huss has shown you will get you the answer

yeah i just noticed i forgot to subtract after i read the question again i edited it  and i said i was missing the R

[LegalEagle24/7]

Two simple suggestions:

Use a highlighter.
Copy out valuable pieces of information CLEARLY stating what it is on the SIDE.

Hi! Some people from my class told us that you can only use a pink highlighter in the HSC exams. Is this true? Thanks

[RuiAce]

Hi! Some people from my class told us that you can only use a pink highlighter in the HSC exams. Is this true? Thanks

Never heard of that rule before. NESA doesn't specify anything regarding the colour either

[LegalEagle24/7]

Never heard of that rule before. NESA doesn't specify anything regarding the colour either

Cool, thanks. Because they said that they only allowed pink as it's the only colour they are able to see when scanning the papers.

[Potatohater]

Cool, thanks. Because they said that they only allowed pink as it's the only colour they are able to see when scanning the papers.

When I did the HSC just a few months ago our supervisor told us not to mark the paper with any highlighters or any implement other than a black pen so....

[RuiAce]

Cool, thanks. Because they said that they only allowed pink as it's the only colour they are able to see when scanning the papers.

If you're unsure it might be a good idea to send them an email. To be fair, they did change their scanning system quite recently (idk why though, it was for the WORSE if you ask me) so no guarantees that things that were ok are still ok. Plus you never know if they update their website.

Having said that though

When I did the HSC just a few months ago our supervisor told us not to mark the paper with any highlighters or any implement other than a black pen so....

That would literally contradict the website itself, which is really odd.
___________________

TLDR: Just email NESA

[jamonwindeyer]

Note that you can highlight any colour you like on the questions, because they don't need to read those

[Lumenoria]

Hey, is there a way to calculate the interquartile range without writing/ordering every single number on paper? Like, say there were 200 numbers, is there a proper formula for this?