Question

How long does it take to triple an investment of $23360 if the investment pays only simple interest at the rate of 5.18% per annum?

Answer 1

wait...

Answer 2

so our principal is 23360?

Answer 3

@mathmale

Answer 4

Where do I start? Ask me questions that lead me to the solution.

Answer 5

Use this equation....

Future Value = Present Value ( 1 + Interest Rate ) ^ N

you know everything except N, so solve for N. Is this clear?

Answer 6

Yes, I've been using that equation for this hw. However, I am having difficulty determining what P and F are. What is principal? Money you start with? The money you barrow or loan?

Answer 7

Those are good questions. You want a investment of $23360 to triple in value, so ideally you know the PV is 23360 and the FV is three times that or 70080. However it is just FV/PV=3 so the equation becomes....

3= (1+IR)^N

Answer 8

I had it setup like this 70080 = 23360(0.0518)*n solve for n

Why is it FV/PV? Is it a ratio?

Answer 9

oh shoot that is the same equation.

Answer 10

oh wait I didn't use the compound interest formula...

Answer 11

To solve your equation divide both sides by 23360. Also you forgot the 1 in (1+0.0518),

Answer 12

Well I thought we were looking at simple interest that is why I used F = P*i*n

Answer 13

because it says simple interest

Answer 14

Oh, I think you are right. It does say simple interest rate. I was thinking it was simple because it wasn't compounded monthly.

Answer 15

okay cool

Answer 16

I got n = 57.91 years

Answer 17

so about 58 years if we round

Answer 18

but it says "simple interest at the rate of 5.18% per annum" so is the interest calculated per annum and added in or not.

Did they given an answer for this question? I got the 57.91 year simple interest and around 21.74 years compounded yearly.

Answer 19

no, I can find out now. I only get three attempts for each hw problem. Let me check because this was my last problem.

Answer 20

nope not correct

Answer 21

Well the question changed....

How long does it take to quadruple an initial investment of $40738 if the investment pays only simple interest at the rate of 10.97% per annum?

Answer 22

Try this and see if you get the right answer...

log(4) / log (1.1097) = 13.318 years

How accurate do they want you to be? How many decimal points?

Answer 23

If the answer is right I can explain it to you.

Answer 24

Is this to the original question or the current question. After I attempt the hw once all the questions change. So I need help with this one

How long does it take to quadruple an initial investment of $40738 if the investment pays only simple interest at the rate of 10.97% per annum?

Answer 25

My previous answer is for the new question. 13.318 years

I think they really wan the interest compounded yearly.

Answer 26

Okay. So how about the question I posted just recently?

Answer 27

YES ----- >>>> 13.318

Answer 28

lol sorry. Let me do the work

Answer 29

this is compound or simple?

Answer 30

I got it... It was compound

Answer 31

can you help me with another problem plz?

Answer 32

Yes that is what I am trying to figure out.

Enter my answer 13.3 years, see if it is correct, then I will know what they are asking for.

Answer 33

I can't... Lol I have to answer all 7 questions before I can submit. I only get 3 times to submit so I have to redo 6 more problems....

Answer 34

here is my other question...

For the cash flow diagram below, which equation demonstrates the correct functional notation that will solve for the unknown Z?

Z = -5000(F/P,8%,4) - 3500(F/P,8%,1) + 2000(F/P,8%,2)
Z = -5000 + 2000 - 3500(F/P,8%,1)
Z = -5000 + 2000(F/P,8%,2) -3500(F/P,8%,1)
Z = -5000 + 2000(P/F,8%,2) - 3500(P/F,8%,3)
Z = -8500(F/P,8%,4) + 2000(F/P,8%,2)

Answer 35

Okay much easier. What do you think?

Answer 36

let me stair at it more

Answer 37

Very good take you time.

Answer 38

does the interest rate account for all the money borrowed or lend?

Answer 39

does it account for the 5 years is what I am asking

Answer 40

Yes.

In the real world, not many people will lend money without charging you interest.

Answer 41

a?

Answer 42

It is A, very good.

Answer 43

wait a min... why is some of them say P/F and F/P

Answer 44

should it be P/F

Answer 45

nvm that is notation. i need to read more about that...

Answer 46

??? I'm not seeing any question.

Answer 47

Jana just received a graduation gift of $43385 from her parents. She decides to deposit it into an account that pays a guaranteed 4% per year, compounded annually. How much will she have in the account when she retires in 28 years?

Answer 48

Here is my next question? Do you want me to make a new thread so I can give you a medal?

Answer 49

Actually I know how to solve this... we use F = P(1+i)^n

Answer 50

Metal is not important, but thanks for asking.

This one uses the equation from before....

Future Value = Present Value ( 1 + Interest Rate ) ^ N

You know everything, so calculate the future value.

Answer 51

F = P(1+i)^n = 43385(1+0.04)^28 = 130098.74

Answer 52

Your typing beat mine, good job.

Answer 53

Davis is saving money for a bicycle trip around the world. He would like to have $23651 saved in 5 years. To reach his goal, how much does Davis need to deposit today in an account paying 7% per year compounded annually?

Answer 54

Next question^^^

Answer 55

Your previous answer was right.

This question is very similar

Future Value = Present Value ( 1 + Interest Rate ) ^ N

now solve for the present value.

Answer 56

so future value is 23651?

Answer 57

yes

Answer 58

P = 16862.84

Answer 59

correct

Answer 60

For his trip, Davis deposited $13479 into an account paying 10% per year, compounded annually. Unfortunately, he had a medical emergency at the end of year 3 and had to withdraw $2114. At the end of year 7 he received a small inheritance and deposited $3408 into his account. How much did Davis have in his account at the end of 12 years?

Answer 61

I think I know how to solve this one. Let me do the work on paper and attach my answer.

Answer 62

Yes this was is easy, but a lot more messy ...

Answer 63

F=13479(1+0.10)^3 = 17940.549

Answer 64

17940.549 - 2114 = 15826.549

Answer 65

Yes. Yes.

Answer 66

It is very good doing in parts and checking. I already have the final answer, but it seems too high to be correct.

Keep going with what you are doing.

Answer 67

F = 15826.549(1+0.10)^2 = 19150.12439

Answer 68

P = 19150.12439 + 3408 = 22558.12429

Answer 69

F=22560.07

Answer 70

Wait a second let me check something

Answer 71

Why did you use TWO years

Answer 72

F = 15826.549(1+0.10)^2 = 19150.12439 Why two years? The end of year 7 from year 3, it should be FOUR years. Right?

Answer 73

oops....

Answer 74

F = 15826.549(1+0.10)^4 = 23171.65

P = 23171.65 + 3408 = 26579.65

F = 26579.65(1+0.10)^7 = 51796.22

Answer 75

Almost let check....

Answer 76

That is not the answer????

Answer 77

F = 26579.65(1+0.10)^7 = 51796.22 This is wrong number of years it is not 7 what should it be?

Answer 78

5

Answer 79

End of year 7, he made the deposit. How much did he have at the end of year 12?

Yes 5.

Answer 80

F = 42806.79

Answer 81

Yep, that' what I got.

You have got to be very careful with the YEARS. Other than that you did great.

Answer 82

Kreskin borrowed $1500 at an annual interest rate of 10% and paid off the loan (principal and interest), after several years with a $1997 check. How many years did it take Kreskin to repay the loan?

Answer 83

Okay I will keep that in mind.

Answer 84

You got this one....

Answer 85

1997 = 1500(1+0.10)^n solve for n

Answer 86

3 years

Answer 87

Yep

Answer 88

If a sum is worth $615 today and it will be worth $731 two years from now, how much was it worth one year ago?

Answer 89

(615+731)/2 = 673

Answer 90

673-615 = 58

Answer 91

I don't know but I don't think it is that simple.

Answer 92

You need to calculate the interest rate some how.

Answer 93

615 - 58 = 557

Answer 94

FV = PV (1+IR)^N

you know everything but IR

Answer 95

673 for every 1 year

Answer 96

Once you know the IR you can find the value at end of year one.

Answer 97

Don't forget the first year will earn less than the second year. Compound interest is still in affect.