The General Chatter Thread.

[Team 9]

greetings from milton keynes college :D

i should be researching monolithic kearnels ^^

[Scourge of teh Galaxy]

greetings from milton keynes college :D

I now know where you live

i should be researching monolithic kearnels ^^

That crap's boring

[Team 9]

if it was interesting, would i be on GTM?

[Scourge of teh Galaxy]

Maybe. I go on GTM all the time in class, whether the class is interesting or not

[Team 9]

well, technically this site is blocked. but i know a loophole in the filter system.

yes, i have used this for pranks

[Scourge of teh Galaxy]

Ugh, I absolutely hate Interest and APR ._.

Any help, guys? Anyone here good with this stuff?

[NFX]

Ugh, I absolutely hate Interest and APR ._.

Any help, guys? Anyone here good with this stuff?

It's just percentages, isn't it? I should be alright with that, what've you gotta do?

[Scourge of teh Galaxy]

Here's the explanation given on the sheet



Calculating APR

There are several ways to calculate APR, but the simplest way is to assume that there are no fees incurred against a loan/credit card.  The APR is then calculated from the compound interest for a year.

Example

For this example you will need a scientific calculator, and know how to use the to the power of button.

If you have a credit card and are charged 2% per month, then
You calculate the compound interest for the year. To do this:
1.   Take the interest rate and divide it by 100 i.e. 2 ÷ 100 = 0.02
2.   Then add the answer to 1 i.e. 0.02 + 1  = 1.02
3.   Then use the power button on your calculator and raise the number to a power of 12  i.e. 1.0212 = 1.2682
4.   Now subtract 1 from the answer i.e. 1.2682 – 1 = 0.2682
5.   And finally multiply the answer by 100 i.e. 0.2682 x 100 = 26.82%.  This gives you the annual percentage rate.

So the annual percentage rate based on 2% per month is 26.82%



It made my brain melt











Calculate the annual percentage rate (APR) for the following monthly payments:

a)   1%
b)   1.5%
c)   2.5%
d)   0.5%
e)   0.75%


Numbers damage my brain, can you tell?

[Jonzu95]

I may buy a dakimakura... owo

[SKBT]

It's Pi day!!!!

[NFX]

Here's the explanation given on the sheet



Calculating APR

There are several ways to calculate APR, but the simplest way is to assume that there are no fees incurred against a loan/credit card.  The APR is then calculated from the compound interest for a year.

Example

For this example you will need a scientific calculator, and know how to use the to the power of button.

If you have a credit card and are charged 2% per month, then
You calculate the compound interest for the year. To do this:
1.   Take the interest rate and divide it by 100 i.e. 2 ÷ 100 = 0.02
2.   Then add the answer to 1 i.e. 0.02 + 1  = 1.02
3.   Then use the power button on your calculator and raise the number to a power of 12  i.e. 1.0212 = 1.2682
4.   Now subtract 1 from the answer i.e. 1.2682 – 1 = 0.2682
5.   And finally multiply the answer by 100 i.e. 0.2682 x 100 = 26.82%.  This gives you the annual percentage rate.

So the annual percentage rate based on 2% per month is 26.82%



It made my brain melt











Calculate the annual percentage rate (APR) for the following monthly payments:

a)   1%
b)   1.5%
c)   2.5%
d)   0.5%
e)   0.75%


Numbers damage my brain, can you tell?

I see. Hopefully I can make things a bit easier.
 
Imagine what you have in the bank doubles each month, or multiplies by 2. So you have £1 to start with, that becomes £2 after one month, £4 after 2, £8 after 3 and so on, until it becomes £4,096 after 12 months. What's happened there is the value you started out with has doubled once for every month it has been in the bank. So 1 become 1x2 after one month, 1x2x2 after two months, 1x2x2x2 after three months, and so on. You can also write this as 1x2^1, 1x2^2 and 1x2^3 respectively. To calculate it over one year, which is 12 months, you could write it as 1x2^12, which is £4096.
 
But whatever it is isn't doubling every month, it's going up by a small percentage. 100% of something is basically multiplying it by one, so adding 2% to the value each month is equal to 102%, or multiplying it by 1.02. So you end up with 1x1.02^12, which comes out as 1.26824. From there, you need to subtract 1, which is the equivelant to removing the 100% of whatever you started with, so you're only left with your interest over the course of the year, which is 0.26824, equivelant to 26.824%.
 
Hopefully that helps. =)

[Scourge of teh Galaxy]

Going by that, that makes it so that a) is 1 x 1.01^12 = 1.126825030131969720661201 - 1 = 0.126825030131969720661201

That did very little to the number beyond adding a load of digits after the decimal place and then minus one o.o

[NFX]

1.01 to 1.1268 is a fair jump. But yeah, that's how you do it, and that is also correct. =) Just make sure that when you get to the 0.5%, you make sure it's 1.005 and not 1.05, which would be 5%.

[Scourge of teh Galaxy]

So, going by that, the answers are



a)   1%
1 x 1.01^12 = 1.126825030131969720661201 - 1 = 0.126825030131969720661201

12.68%

b)   1.5%
1 x 1.015^12 = 1.1956181714615352515612900979004 – 1 = 0.1956181714615352515612900979004

19.56%

c)   2.5%
1 x 1.025^12 = 1.3448888242462984371781349182129 – 1 = 0.3448888242462984371781349182129

34.49%

d)   0.5%
1 x 1.005^12 = 1.0616778118644995687897076174316 – 1 = 0.0616778118644995687897076174316

6.17%

e)   0.75%
1 x 1.0075^12 = 1.0938068976709830629654555485869 – 1 = 0.0938068976709830629654555485869

9.38%


Yes? :>

[NFX]

Bang on. =)

[Jonzu95]

Eh...? I'm glad I didn't go to college.

[Scourge of teh Galaxy]

...good god. The final hurdle... is Credit Card Payments





Worked Example – Credit Card Payments


If you receive a credit card bill for £567 and the repayment conditions are:
•   The minimum monthly repayment is 12% of the total bill
•   The monthly interest rate is 3%

How much do you still owe at the end of three months?

Solution
For each month, you need to:
1.   Calculate the monthly payment
2.   Subtract the monthly payment from the bill.
3.   Calculate the interest
4.   Add the interest on

Month 1
1.   Re-payment is 12% of the total bill i.e.
12% of £567  (12 ÷ 100) x 567      =  £68.04

2.   Bill is reduced to £567 - £68.04     =  £498.96

3.   Interest is 3% of £498.96   = (3 ÷ 100) x 498.96          =  £14.97

4.   The bill at the end of month 1    =  £498.96 + £14.97      =  £513.93


Month 2
1.   Re-payment is 12% of the total bill i.e.
12% of £513.93  (12 ÷ 100) x 513.93 =  £61.67

2.   Bill is reduced to £513.93 - £61.67     =  £452.26

3.   Interest is 3% of £452.26   = (3 ÷ 100) x 452.26         =  £13.57

4.   The bill at the end of month 1    =  £452.26 + £13.57      =  £465.83


Month 3
1.   Re-payment is 12% of the total bill i.e.
12% of £465.83  (12 ÷ 100) x 465.83 =  £55.90

2.   Bill is reduced to £465.83 - £55.90     =  £409.93

3.   Interest is 3% of £409.93   = (3 ÷ 100) x 409.93         =  £12.30

4.   The bill at the end of month 1    =  £409.93 + £12.30      =  £422.23



My brain melted again




LUCKILY, there's only two questions this time (thank god, numbers kill me ._.)


Question 1

You receive a credit card bill for £358.  If the monthly rate of interest is 2%, how much will you still owe at the end of 4 months if you pay the minimum payment of £35 per month?











Question 2

A credit card bill totals £1260.  If the minimum payment is 15% of the remaining bill, how long will it take to bring the bill down below £1000 if the monthly interest rate is 4%?

[Fracture]

I think you could have solved those problems yourself in the time it took you to actually type them out onto GTM. :P

Unless they were already stored electronically.

[Scourge of teh Galaxy]

I think you could have solved those problems yourself in the time it took you to actually type them out onto GTM. :P

Unless they were already stored electronically.

Copy/paste is a wonderful thing

[Incredirobotwars]

Eh, I can't deal with stuff that's just numbers. I'm pretty epic at algerbra with final numeric values. I don't like leaving everything in variables. I can also do Calculus and complex numbers relatively easily. I hated this percentage shiz when I used to do it.

Also, I can do a lot of VBA, because I have been doing it constantly for the past year.