VCE General & Further Maths Question Thread!

[PhoenixxFire]

I'm just confused with why interest equals total amount of payments - Pv.

The interest is the difference between the amount you borrowed (Pv) and the amount you payed back (total payments). So to work out the difference you subtract the amount you borrowed from the amount you payed back and you're left with the interest that you payed.

[studyingg]

I'm just confused with why interest equals total amount of payments - Pv.

Also, just to add to what PhoenixxFire said, when you think about it, what is a reducing balance loan? Its comprised of three components
-the amount owed to the bank
-the payment value made every period
-and the interest rate

Each compounding period (month or quater or whatever) the  loan will increase by a certain amount, as interest would have been added to it. However, we reduce the balance of the loan by making our periodic payment, that decreases the amount we owe to the bank. However when we make this payment not only are we paying off the loan that we owe to the bank, but we are also paying off the interest that is added to it. In this way, our payments are not only paying off the loan, but also the interest that is calculated on the loan... as how else could the bank make a prophet? We can figure out how much interest we paid the bank in total, by calculating how much money we gave them to pay off the loan in total. (which is number of payments * payment) or (N * pmt). This is all the money we gave the bank to pay off our loan...but for some reason this amount is always higher than the initial amount of money we put in the bank (V0/ PV), because this money was also used to pay off interest, therefore we can calculate exactly how much of the amount that we paid went to paying interest by simply finding the difference between the amount we paid, and the initial value of the loan.

[PopcornTime]

Thanks for all your help phoenix + studyinggg.

Also, I put A for this question. Why would the answer be E?

[S200]

J is to L as K is to M?

[passbleh24]

Hey I have a question regarding the study design.
I just completed the 2012 Further Exam 1, and came across this question. I've attached it below.
It involves infinite geometric sequences and is quite strange. Is this type of question still a part of the study design? Would I need to learn how to do them?

Thank you for any input.

[studyingg]

Hey I have a question regarding the study design.
I just completed the 2012 Further Exam 1, and came across this question. I've attached it below.
It involves infinite geometric sequences and is quite strange. Is this type of question still a part of the study design? Would I need to learn how to do them?

Thank you for any input.

If you are referring to financial maths, then no you don't need to know these type of sequences, as the only geometric and arithmetic sequences we need to know are first order relationships.

[Lear]

Hey I have a question regarding the study design.
I just completed the 2012 Further Exam 1, and came across this question. I've attached it below.
It involves infinite geometric sequences and is quite strange. Is this type of question still a part of the study design? Would I need to learn how to do them?

Thank you for any input.

No, you do not need to know infinite sums anymore. Just a heads up, most of the number patterns module is no longer really relevant. The only thing vaguely useful is recurrence relations which VCAA predominantly just relates directly to financial math.

[Lear]

A loan of $15,000 is taken out compounding monthly with an interest rate of 4.5% Per annum. Payments are also made monthly and the loan will be paid off in 7 years.
a) What is the monthly payment
b) How much interest is paid in the first two years.

For part b I seem to be getting different answers depending on if I make a reducing balance table and sum up the interest for each payment compared to using Financial solver.
Which method is correct?

[studyingg]

A loan of $15,000 is taken out compounding monthly with an interest rate of 4.5% Per annum. Payments are also made monthly and the loan will be paid off in 7 years.
a) What is the monthly payment
b) How much interest is paid in the first two years.

For part b I seem to be getting different answers depending on if I make a reducing balance table and sum up the interest for each payment compared to using Financial solver.
Which method is correct?

I got $1187.94 using the TVM, I think its correct... I feel like the other method is more time consuming because you have to fill in the table up to 24 payments.

[Lear]

I got $1187.94 using the TVM, I think its correct... I feel like the other method is more time consuming because you have to fill in the table up to 24 payments.

You're right. But a counter argument is that it is 'more correct' as TVM incurs rounding errors whereas the table doesn't. I get 1187.9986 using table.

[passbleh24]

Hey I have a question about the study design again.

For this question in 2013, it asks for the effective rate of interest. I know the difference between nominal and effective annual interest when its referring to compound interest but i don't understand what they're doing here at all.
What formula are the using? Is this something that isn't in the study design.

Thank you for any input.

[galaxy21]

Hey I have a question about the study design again.

For this question in 2013, it asks for the effective rate of interest. I know the difference between nominal and effective annual interest when its referring to compound interest but i don't understand what they're doing here at all.
What formula are the using? Is this something that isn't in the study design.

Thank you for any input.

Hey,
I'm pretty sure this is from the old study design. I know our school taught us this way last year (Units 1/2), but said not to use it this year as effective rate of interest means something different. I would disregard these questions if they are from the old study design, as we no longer use this effective rate of interest.

[studyingg]

I have a question about significant figures, this question required the value of 109.894 to be rounded to 3 significant figures, so how is 110 correct? I thought trailing zeros in non-decimal numbers are not significant? If this is the case... how would we round this number to 3 sigfig?

[galaxy21]

I have a question about significant figures, this question required the value of 109.894 to be rounded to 3 significant figures, so how is 110 correct? I thought trailing zeros in non-decimal numbers are not significant? If this is the case... how would we round this number to 3 sigfig?

The guidelines for significant figures is as follows:
- All digits greater than zero are significant
- All zero's between significant digits are significant
- All zero's before non-zero digits are not significant
Regarding zero's after the decimal place
- If they fall before a decimal place, they are not significant
- if they fall after a decimal place, they are significant.

For the number 109.894, as the first digit, 1, is greater than zero, this is the first significant figure, and there are significant decimal numbers, the three numbers before the decimal place would be significant. As the following number, 8 is greater than 4, we round up the last digit from 9 to 10. Even though normally 110 would be 2 significant figures as the last value, zero, is before the decimal place, if we take in normal rounding laws, this is the only way that this can correctly be founded to 3 sig fig

Just as an idea, if 109.894 was asked to be rounded to different sig fig values...
1 sig fig:100
2 sig fig: 110
3 sig fig: 110
4 sig fig: 109.9
5 sig fig: 109.89
6 sig fig: 109.894


Sorry...reading that back to myself seemed a little confusing. Give me a yell if it makes no sense 

[Further Maths 101]

Is it worth doing the NSW (HSC) bostes exam?