Suppose that $P$ dollars in principal is invested at an annual interest rate $r$. For interest compounded $n$ times per year, the amount $A(t)$ in the account after $t$ years is given by $A(t)=P\left(1+\frac{r}{n}\right)^{n t}$. If interest is compounded continuously, the amount is given by $A(t)=P e^{n} .$
Suppose an investor deposits $\$ 10,000$ in an account earning $6.0 \%$ interest compounded continuously. Find the total amount in the account for the following time periods. How does the length of time affect the amount of interest earned?
a. $5 \mathrm{yr}$
b. $10 \mathrm{yr}$
c. $15 \mathrm{yr}$
d. $20 \mathrm{yr}$
e. $30 \mathrm{yr}$