Question

kelly has a $3,000 balance on her credit card with an 18% interest rate. if she makes no payments on her card and no late fees are charged, how long will it take for her debt to double if its compounded quarterly?

Answer 1

@LGND_88

Answer 2

halp pls @wanell

Answer 3

@3mar

Answer 4

@paki

Answer 5

i know that the formula for interest is \[A=P _{0}(1+\frac{ r }{ n })^{n*t}\]

Answer 6

but i don t know how to set it up

Answer 7

*compound interest i mean*

Answer 8

@Luigi0210 @sammixboo @Awolflover1

Answer 9

@MathSucks321

Answer 10

I suck at these sorry T_T Plus I have to finish my work that I decided to start today! And it is due Friday.

Answer 11

i would probably be able to do this on my own but i have ADHD so i need music to focus......at the same time the music makes it difficult for me to think. (cuz i listen to hardstyle, dubstep, etc) so its a trade-off. do i want to be able to think and not focus, or focus and not be able to think. T_O

Answer 12

@dehydrated

Answer 13

@pooja195

Answer 14

@zepdrix @IrishBoy123

Answer 15

i need help ASAP

Answer 16

help me out @518nad please.....been waitin for over an hour

Answer 17

kelly has a $3,000 balance on her credit card with an 18% interest rate. if she makes no payments on her card and no late fees are charged, how long will it take for her debt to double if its compounded quarterly?

Answer 18

okay this is something financial people do and its a bit.. ambiguous, when they say 18% interest rate compounded quarterly, what they really mean is 18/4% interest rate is compouneded every single quarter

Answer 19

alright...

Answer 20

18/4 = 4.5%

Answer 21

so every quarter ur compounding 4.5%

Answer 22

k.

Answer 23

so 4.5% of 3000 is........

Answer 24

crap forgot the formula...

Answer 25

3000(1+0.045)
^---------- 4.5%

Answer 26

ok. hang on...

Answer 27

so thats what u have to pay after 1 quarter

Answer 28

3000(1+0.045)(1+0.045) after 2 quarters
3000(1+0.045)(1+0.045)(1+0.045) after 3 quarters
3000(1+0.045)^n after n quarters u want to know how many quarters it takes to get to double of 6000
3000(1+0.045)^n=6000, solve for n

Answer 29

k gimmie a sec.

Answer 30

srry got kicked

Answer 31

3000(1+0.045)^n=6000

Answer 32

ehhhhmmm.... i got 1.49577e118

Answer 33

3000/3000(1+0.045)^n=6000/3000
(1+0.045)^n=2
1.045^n=2
n log 1.045 = log 2
n=log2/log1.045

Answer 34

log2/log1.045=15.7473
15.7474 quarters, so thats almost 4 years

Answer 35

wow. thx

Answer 36

i got another one if ur up to it

Answer 37

ya if u really understand this question

Answer 38

What if kellys APR was 22% and she makes no payments on her card and no late fees were charged? (use the same information from #15 to find out how many years it would take her 3000 debt to double)

Answer 39

okay try to do this urself, show me ur work

Answer 40

the only difference here is the 18% is now 22%

Answer 41

ok, im not going to lie, i dont understand your descripion. can you use the equation tab to show me how to do this in formula form?

Answer 42

okay lets start with this

Answer 43

lets consider a simpler example 40% annual rate, how much percentange is this compounded quarterly?

Answer 44

10%

Answer 45

right

Answer 46

so now lets see whats going on here, that means every quarter we have a 10% increase in what we curently have

Answer 47

which is $30

Answer 48

First quarter we must pay a total of 3000(1+0.1)

Answer 49

or $300 my bad

Answer 50

its 3300 total u have to pay

Answer 51

ah

Answer 52

one step at a time, do u understand this:
First quarter we must pay a total of 3000(1+0.1)

Answer 53

hey?

Answer 54

please be straight forward its okay to say u dont understand if u dont

Answer 55

srry replying to a message

Answer 56

okay can u pay attention for 5 mins

Answer 57

if u can bear with me for 5 mins ill teach u everything u need to know about compounding that ull be able to derive urself

Answer 58

i would probably be able to do this on my own but i have ADHD so i need music to focus......at the same time the music makes it difficult for me to think. (cuz i listen to hardstyle, dubstep, etc) so its a trade-off. do i want to be able to think and not focus, or focus and not be able to think. THANK YOU VERY MUCH!!!! >:(

Answer 59

okay lets forget about everything that tells u u cant do this right now and focus on the question im asking u its simple

Answer 60

Do you understand :
First quarter we must pay a total of 3000(1+0.1)

Answer 61

yea

Answer 62

simple equation

Answer 63

so far at least...

Answer 64

do u understand this
first quarter
3000+3% of 3000

Answer 65

yes

Answer 66

3000+10% of 3000
3000+0.1*3000, factor the 3000
3000(1+0.1)

Answer 67

this is task 1 to get into this simplified form

Answer 68

OOOOH. ok i get it. you got the 0.1 by moving the decimal 2 times to the left becaise of the 100% thing. ok cool.

Answer 69

yes

Answer 70

okay now are u sureee u get
3000(1+0.1)

Answer 71

other wise the rest will confuse u

Answer 72

yea

Answer 73

shoot

Answer 74

let me just explain just ot be sure again

Answer 75

T_T fine

Answer 76

3000(1+0.1)
the (1+0.1) what is that doing to this 3000? its taking that 3000 and then adding 10% of that 3000 to itself

Answer 77

ok.

Answer 78

3000(1+0.1), so this is the current total to pay at first month, at the 2nd month u must tke this whole price and add 10% of to that new price

Answer 79

which is why u multiply by another (1+0.1)
3000(1+0.1)(1+0.1) price to pay for 2nd quarter

Answer 80

does that make sense?

Answer 81

yea. one ques, is this calculator-safe?

Answer 82

the equation imean

Answer 83

hmm what?

Answer 84

like, can you input this into a TI-nspire calculater and it will work?

Answer 85

3000(1+0.1)(1+0.1)
=3000(1+0.1)^2 for 2 quarters
3000(1+0.1)^n for n quarters

Answer 86

ya um try to understand this logic

Answer 87

3000(1+0.1)^n
P(1+r)^n
thus u get this equation

Answer 88

oh ok so the formula would be 3000(1+0.22)^n?

Answer 89

:<

Answer 90

yes, but remember n is the number of quarters here

Answer 91

which is unknown atm

Answer 92

yes so solve for n, and divide by 4 to turn the quarters into years

Answer 93

or ots 15.7474

Answer 94

oh

Answer 95

thats for hte previous question not this one

Answer 96

yea i figured too late