compound int. formula with regular deposits, solve for time

[zarles]

I cant seem solve the following problem due to my bad memory of logarithms

if someone opens an account with initial balance of B
interest rate of R
and does a constant monthly deposit of D

how long before the account balance reaches X ?

 

[tkhunny]

Re: compound int. formula with regular deposits, solve for t

You'll have to be more explicit about the interest rate.

Is "R" annual interest? Is it compounded monthly?

You're not yet anywhere near logarithms on this problem.

 

[zarles]

Re: compound int. formula with regular deposits, solve for t

R is annual

 

[soroban]

Re: compound int. formula with regular deposits, solve for t


Sheesh!

Yet another problem expecting us to derive the Annuity Formula.
. . (And they always sneak it in under "compound interest".)

I can do it, but it's really not worth the effort . . .Do a search for the formula.

 

[tkhunny]

Re: compound int. formula with regular deposits, solve for t

R is annual

I just knew you were going to do that.

1) You answered only one of my two questions.
2) You still managed to show no effort at all.

You must do better than that.