## toxicsugar22 Group Title What rate of interstis required so that $1000 will yield$1900 after 5 years if the interset rate is compounded monthly. And I got 12.9% Now How long will it take a sum of money to triple if it is invested at 10% compounded daily 3 years ago 3 years ago

1. heisenberg Group Title

there is a formula for this. do you know it / did you use it for the first question?

2. toxicsugar22 Group Title

yes it is A=P(1+r/n)^nt

3. heisenberg Group Title

ok so: r = .10 n = 365 A = 3*P $3*P = P*(1+\frac{.1}{365})^{.1*t}$solve for t.

4. toxicsugar22 Group Title

so what do we do know

5. toxicsugar22 Group Title

do i divide by 3

6. heisenberg Group Title

well you can start by dividing by P to get rid of it. then you will need to solve for t, which will involve using logarithms.

7. toxicsugar22 Group Title

so 3=p(1+10/365)^365/t

8. toxicsugar22 Group Title

is it right

9. heisenberg Group Title

no. after dividing by P:$3= (1+\frac{.1}{365})^{.1*t}$

10. heisenberg Group Title

then you must use logarithms. I use ln which is log_e, the natural log. $\ln(3)= .1*t*\ln(1+\frac{.1}{365})$ then solve for t.

11. toxicsugar22 Group Title

ok can you help me do that it really hard for me

12. toxicsugar22 Group Title

13. heisenberg Group Title

so remember, what you do to one side of the equation, you must do to the others. since we want t by itself, we can divide by the other terms to isolate it, like so: $\frac{\ln(3)}{\ln(1+\frac{.1}{365})} = .1*t$ then divide by .1 and you will have t by itself.

14. toxicsugar22 Group Title

ok can u help more

15. heisenberg Group Title

what do you not understand?

16. toxicsugar22 Group Title

the log

17. toxicsugar22 Group Title

its so complicated

18. heisenberg Group Title

can you use a calculator?

19. toxicsugar22 Group Title

maybe if you go step by step with me then i will get it

20. toxicsugar22 Group Title

yes i can use a calc.

21. toxicsugar22 Group Title

i can but i still need help

22. heisenberg Group Title

take the log(3), then divide by the other log. then divide by .1

23. toxicsugar22 Group Title

ok log 3 is .47712125

24. toxicsugar22 Group Title

now i divide by what

25. heisenberg Group Title

log(1+.1/365)

26. toxicsugar22 Group Title

i got 1.18968

27. toxicsugar22 Group Title

is it right

28. toxicsugar22 Group Title

is it right

29. toxicsugar22 Group Title

i got .4010500723

30. heisenberg Group Title

how did you get 1.18968? you must do the inside of the parentheses first. here is it in an online calculator: http://www.wolframalpha.com/input/?i=log%281%2B.1+%2F+365%29&a=*FunClash.log-_*Log10.Log-

31. toxicsugar22 Group Title

ok But isnt it .10 instead of .1

32. toxicsugar22 Group Title

because it wat to know How long will it take a sum of money to triple if it is invested at 10% compounded daily

33. heisenberg Group Title

those are the same number! .1 = .10 = .100 = .10000000

34. toxicsugar22 Group Title

35. heisenberg Group Title

can you not calculate it? it would be better then me just giving it to you.

36. toxicsugar22 Group Title

i tried

37. toxicsugar22 Group Title

ut i got a weird answer and im not sure i got it right

38. heisenberg Group Title
39. toxicsugar22 Group Title

it 40104.8

40. toxicsugar22 Group Title

is that it

41. heisenberg Group Title

that doesn't seem right though, heh. does it?

42. toxicsugar22 Group Title

no it doesnt

43. heisenberg Group Title

because i messed up! it is n*t, not r*t. so you should not divide by .1, but by 365

44. toxicsugar22 Group Title

ok

45. toxicsugar22 Group Title

so now can u help again

46. heisenberg Group Title

you should try and do these yourself on a calculator. you can type it in on this site if you want even. http://www.wolframalpha.com/input/?i=log%283%29+%2F+log%281%2B.1+%2F+365%29+%2F+365&a=*FunClash.log-_*Log10.Log-

47. toxicsugar22 Group Title

yes

48. toxicsugar22 Group Title

You do it also and then we will compare aur answers

49. toxicsugar22 Group Title

okay

50. heisenberg Group Title

i just did it. click on that link. it is an online calculator.

51. toxicsugar22 Group Title

ok i got 10991.6

52. toxicsugar22 Group Title

is that what you got

53. heisenberg Group Title

no. click on the link to see. http://www.wolframalpha.com/input/?i=log%283%29+%2F+log%281%2B.1+%2F+365%29+%2F+365&a=*FunClash.log-_*Log10.Log-

54. toxicsugar22 Group Title

ok thanks

55. toxicsugar22 Group Title

im going to give you a medal and be your fan if you be my fan

56. toxicsugar22 Group Title

do u agree

57. toxicsugar22 Group Title

u there