Question

How long it will take for $300 to double when invested at 6% annual interest compounded twice a year?

Answer 1

\[A=P(1+\frac{r}{n})^{nt}\]P = principal amount (the initial amount you borrow or deposit)
r = annual rate of interest (as a decimal)
t = number of years the amount is deposited or borrowed for.
A = amount of money accumulated after n years, including interest.
n = number of times the interest is compounded per year.

Memorize this formula.