Standard Math Q+A Thread

[RuiAce]

Guys come on. You're free to rant all you like but please just dump it all here. Let's keep this thread cleaner for next year's cohort to ask questions

[lilly.n]

hi, i need some help for this question (it is year 11 General math btw)

[RuiAce]

hi, i need some help for this question (it is year 11 General math btw)

c) is the exact same, just that the thereafter becomes $60000

a) differs in that there is NO thereafter, as we never pay more than $140000. The next $120000 instead becomes the next $80000

[Kira Leigh]

Hi there
We just got results back from our first HSC task and everyone was pretty confused with this one question.

B)  A kebab shop offers six different fillings for their kebabs. If Jo chooses three fillings for a kebab how many different possible choices could he make?
Everyone assumed because it said different to use the
6x5x4
Can someone please explain why we were wrong?

[jamonwindeyer]

Hi there
We just got results back from our first HSC task and everyone was pretty confused with this one question.

B)  A kebab shop offers six different fillings for their kebabs. If Jo chooses three fillings for a kebab how many different possible choices could he make?
Everyone assumed because it said different to use the
6x5x4
Can someone please explain why we were wrong?

Hey Kira! Interesting - I'd assume you are right! However, the question never specifies that out of the 6 different fillings, that the 3 choices need to be different. That is, they could choose the same filling three times! So, it becomes 6x6x6 the choices don't have to be different, that's the discrepancy! Although the 6 choices are all different the choices don't have to be

(but then why would you choose triple of the same filling lol)

[DalvinT]

Hey all! I've had a massive amount of people asking for somewhere to get some help with General Mathematics content. Now, I didn't do the course myself, but I've done a lot of it in my own studies, either at the HSC level or even at uni (yes, General Math students are better at statistics than MX2 students, I didn't learn stats until I got to university) 

So, here is a place to ask questions!! I'll do my best to answer what I can, or I'd love to see you guys helping each other out as well! You'll answer it better than I could, and plus, teaching others is the best way to learn content, so helping out a peer is a win-win situation 

I hope everyone is going well with their studies 

PS - Remember to check out our free HSC lectures this July, including General Math!

Hey Jamon!!

My problem is usually with the practice exams! And I know, people have been telling me to do more practice papers to get better at those Band 6 Questions. But honestly, I think the real problem is with the "thinking process" that is involved.


For example, if we get a Band 6 Trig Question and it's very unfamiliar... What is the thinking process that you or anyone who is a Band 6 in Mathematics undergo?

i hope my question make sense hahah...

[RuiAce]

Hi there
We just got results back from our first HSC task and everyone was pretty confused with this one question.

B)  A kebab shop offers six different fillings for their kebabs. If Jo chooses three fillings for a kebab how many different possible choices could he make?
Everyone assumed because it said different to use the
6x5x4
Can someone please explain why we were wrong?

Hey Kira! Interesting - I'd assume you are right! However, the question never specifies that out of the 6 different fillings, that the 3 choices need to be different. That is, they could choose the same filling three times! So, it becomes 6x6x6 the choices don't have to be different, that's the discrepancy! Although the 6 choices are all different the choices don't have to be

(but then why would you choose triple of the same filling lol)

I don't know enough about kebabs (shame), but just out of curiosity does the ordering of the fillings matter?

[Kira Leigh]

Hey Kira! Interesting - I'd assume you are right! However, the question never specifies that out of the 6 different fillings, that the 3 choices need to be different. That is, they could choose the same filling three times! So, it becomes 6x6x6 the choices don't have to be different, that's the discrepancy! Although the 6 choices are all different the choices don't have to be

(but then why would you choose triple of the same filling lol)

Thank you!! That makes sense 

[jamonwindeyer]

Hey Jamon!!

My problem is usually with the practice exams! And I know, people have been telling me to do more practice papers to get better at those Band 6 Questions. But honestly, I think the real problem is with the "thinking process" that is involved.

For example, if we get a Band 6 Trig Question and it's very unfamiliar... What is the thinking process that you or anyone who is a Band 6 in Mathematics undergo?

i hope my question make sense hahah...

Hey hey, it sure does! And you are going to hate the answer... It's practice. I feel like a broken record at times but practice is literally the most effective study method for any level of Math.

So when I get a Band 6 Trig question (one targeting Band 6 level students), I draw on my previous experiences of past exams, other questions I've done. I have patterns that I've seen before, I have things in the back of my mind that worked before and could work again. By the end of the HSC, almost no question could surprise me because I'd seen enough questions to know where a question needed me to go, before I ever started

There are of course little strategic tricks too. You should identify a topic first, for example, to narrow down your plan of attack. But the best way to get better at those unfamiliar questions, is to attempt unfamiliar questions and then learn from the solution. Never leave a math question unsolved. You should always use the solution to learn from a question, whether you can answer it on the spot or not

[jamonwindeyer]

I don't know enough about kebabs (shame), but just out of curiosity does the ordering of the fillings matter?

Well if this is a HSP then the order definitely matters. To the shops who put cheese on TOP of the meat, not within or below, then shame on you. Shame.

But for a kebab the order definitely doesn't matter

[RuiAce]

Hey Jamon!!

My problem is usually with the practice exams! And I know, people have been telling me to do more practice papers to get better at those Band 6 Questions. But honestly, I think the real problem is with the "thinking process" that is involved.


For example, if we get a Band 6 Trig Question and it's very unfamiliar... What is the thinking process that you or anyone who is a Band 6 in Mathematics undergo?

i hope my question make sense hahah...

If it targets band 6, you're not supposed to have seen it before.

Hence the emphasis on "thinking process". Because you've never seen it before, you're not going to have something right up your sleeve to directly attack the problem. If you do, it means you were already at the band 6 level, which at this point in the year most people are not.

For your first few problems, you might just think for a while and not find anything. So don't be hesitant to just look at the answer.

Then, as Jamon said, look for any patterns. Compare the thought process involved in using whatever rule they applied. See if there's any reason why they, for example, made a good choice picking the sine rule over the cosine rule and etc.

Well if this is a HSP then the order definitely matters. To the shops who put cheese on TOP of the meat, not within or below, then shame on you. Shame.

But for a kebab the order definitely doesn't matter

Pfft I will never have an HSP, too oily.

Well, if the order doesn't matter, don't you have to divide out by 3x2x1 (ignoring factorials at a general level because I dunno if they get taught it)

[jamonwindeyer]

Well, if the order doesn't matter, don't you have to divide out by 3x2x1 (ignoring factorials at a general level because I dunno if they get taught it)

Hmmm... Nah, maybe the order matters then... I shall ask Steph

[stephanieazzopardi]

Hi there
We just got results back from our first HSC task and everyone was pretty confused with this one question.

B)  A kebab shop offers six different fillings for their kebabs. If Jo chooses three fillings for a kebab how many different possible choices could he make?
Everyone assumed because it said different to use the
6x5x4
Can someone please explain why we were wrong?

Hi Kira Leigh!
So the reason why you 6 x 5 x 4 wouldn't give you the correct answer is because that is not taking into account that this is an unordered selection meaning that the order doesn't matter.
To answer correctly, you need to use the combination function on your calculator or solve through a fraction.

• Using the combination function (Shift > ÷), it would \( 6 C 3 \) because there are 6 possible fillings but we only want to choose 3, which equals 20 possible choices
• Using a fraction, it would be \(\frac{6 × 5 × 4}{3 × 2 × 1}\) which equals 20 possible choices

Going back to what Jamon said about being able to choose one filling twice, I think the question and most questions like this assumes that the person wouldn't pick the same filling twice 

I hope that helps and makes sense! 

[Celina muscat]

Hello, I'm finding it difficult to understand the trigonometry topic and really need some help solving this math's question.

[RuiAce]

Hello, I'm finding it difficult to understand the trigonometry topic and need some help solving this math's question.
I need to find the value of angle A in the triangle ABC. I am given the side length of AB which is 14cm and the side length of BC which is 9cm. I am then given angle C which is 48 degrees. I am meant to use the sin rule but I am unsure how to put this into a formula to solve it.
Thank you in advance