## 00kirsten Group Title Linda invests $5000 into an account that pays 11% compounded quarterly. How much interest will she get after 5 years? 3 years ago 3 years ago • This Question is Closed 1. nowhereman Group Title Is her gain reinvested instantly or paid out? 2. 00kirsten Group Title i dont no. thats the exact question. i copied n pasted it 3. nowhereman Group Title http://en.wikipedia.org/wiki/Compound_interest It is revinvested. That means you have to calculate $5000\cdot 1.11^{4\cdot 5}$ 4. 00kirsten Group Title wait how do i write 11% ??? 0.11 or 1.11 ??? ... and i dont no how to do that equation on a calculator 5. BecomeMyFan=D Group Title the final answer is 35311.56$

6. BecomeMyFan=D Group Title

you do it like this:

7. nowhereman Group Title

11% = 0.11 but the original sum remains there too, so you have 1 + 11% = 1.11

8. BecomeMyFan=D Group Title

$5000(1+(11/100))^{5*4}$

9. BecomeMyFan=D Group Title

got it?

10. 00kirsten Group Title

this is how i wrote it .. .A = 5000 (1 = 0.11/4) 4x5

11. BecomeMyFan=D Group Title

no, that is wrong

12. 00kirsten Group Title

i cant seem to figure that out on a calculator, u told me the answer but i cant get it on the calculator

13. nowhereman Group Title

Is it 11% anually or quarterly?

14. 00kirsten Group Title

i meant to write 1 + 0.11

15. 00kirsten Group Title

quarterely

16. BecomeMyFan=D Group Title

ok, the full formula for compound interest is this $A=P(1+rate)^{number of years * timez per year}$ so the timezperyear is 4 in your case as there are 4 quoters in a year

17. nowhereman Group Title

Ok, so that /4 was a mistake of yours. Well, what kind of functions does your calculator have? Is there a button that says "a^b" or maybe "x^y" ? Or otherwise there maybe buttons for "exp" and "ln"

18. 00kirsten Group Title

umm im doing it on my cellphone calculator so no

19. BecomeMyFan=D Group Title

in a calculator it would look like A=P(1+rate)^(numberofyears∗timezperyear)

20. BecomeMyFan=D Group Title

damn, you should get a casio fx series

21. nowhereman Group Title

you can also do it on google or wolframalpha

22. BecomeMyFan=D Group Title
23. BecomeMyFan=D Group Title
24. 00kirsten Group Title

sooo how do i write down the equation

25. BecomeMyFan=D Group Title

it can solve integrals, derivatives, logarithms, anything

26. nowhereman Group Title
27. BecomeMyFan=D Group Title

like this: A = 5000(1+(11/100))^5∗4

28. BecomeMyFan=D Group Title

which is: = 5000(1.11)^20

29. BecomeMyFan=D Group Title

which is A = 5000 * 8.062311536 = 40311.55768 so now to get the compound interest subtract the 5000 from the answer, CI=40311.55768-5000 =35311.56

30. 00kirsten Group Title

ok thank uu

31. 00kirsten Group Title

one more?? Using the rule of 72, how long will it take to double your money if you invest in an account earning 3% interest? Give units of time (days, weeks, months, or years)

32. BecomeMyFan=D Group Title

24 years

33. 00kirsten Group Title

ok i got it right thx :)

34. BecomeMyFan=D Group Title

you just divide 72 by the percentage

35. 00kirsten Group Title

wat does it mean tho by give units of time (days,weeks, months, years???

36. BecomeMyFan=D Group Title

or, if the question asks you how long it takes for the money to halve, divide 72 by percentage :)

37. BecomeMyFan=D Group Title

it is there because the answer is not always in years, for example, if a question asks you how long it takes to double your money if you invest in an account earning 80% interest. It is IMPOSSIBLE in real life, but some questons might ask that, so, 72/80=0.9, which is 0.9 year, which is 365/10*9=328.5=329days

38. BecomeMyFan=D Group Title

get it? but most of the times the answer is in years, so dont worry

39. 00kirsten Group Title

can you see if these are right for me please. 6. Find the simple interest on $500 for 3 years at 7%. is it like this 500 x 0.07 x 3 =$105 7. Find the simple interest on $800 at 8.75% for 100 days. is it like this$800 x .0875 x 100/365 = $19.18 40. BecomeMyFan=D Group Title 6. is right 7. is right 41. 00kirsten Group Title sweet thanks and is this one right ... (last one) How much money would you have to invest to make$300 within 2 years if the interest rate was 4.5%? is the answer \$3333.33

42. 00kirsten Group Title

i think like 3 diff people gave me different answers, so im so confused!!

43. BecomeMyFan=D Group Title

thats right