Suppose you invest 𝑃 dollars in a bank account that earns 𝑟% annual interest, compounded quarterly. Then the balance 𝐴 in the account after 𝑛 years is given by the formula:

Question

A=P(1+r/400)^(4n)

Assume you know the rate of interest, r%, how much money you invest, P, and how much money you want to make, A. You can now solve this equation for n, which will give you an idea about how many years you need to invest the money for. What is the formula for n, in terms of P, A, and r?

n=

Answer 1

Suppose you invest 𝑃 dollars in a bank account that earns 𝑟% annual interest, compounded quarterly. Then the balance 𝐴 in the account after 𝑛 years is given by the formula:

A=P(1+r/400)^(4n)

Assume you know the rate of interest, r%, how much money you invest, P, and how much money you want to make, A. You can now solve this equation for n, which will give you an idea about how many years you need to invest the money for. What is the formula for n, in terms of P, A, and r?

Hello Boo,

Solve for n, why didn't you just say so...

A = P(1+ r/400)⁴ⁿ

A/P = (1+ r/400)⁴ⁿ

Ln [A = P(1+ r/400)⁴ⁿ]

Ln[A/P] = Ln(1+ r/400)⁴ⁿ

Ln[A/P] = 4n*Ln(1+ r/400)

n = Ln[A/P] / 4Ln(1+ r/400)

_{Lets Go Brandon!}