Task $1$:

Karl deposits DKK $4,000$ in the bank at a fixed annual interest rate of $2\mathrm{.}9\%.$

a$)$ How much money will be in the account after $5$ years?

Karl's girlfriend deposits DKK $4,000$ in another bank. After $5$ years, the amount has

grown to DKK $4,705.$

b$)$ Determine the annual percentage rate for this bank.

Formel:

the interest formula:

$K_n=K_0*(1+r{)}^n.$

Annuity savings:

$A_n=y*\frac{(1+r{)}^n-1}{r}.$

Annuity loan where the benefit y must be calculated:

$y=G*\frac{r}{1-(1+r{)}^{-n}}.$

Annuity loan where the term $n$ must be calculated:

$n=-\frac{log(1-\frac{G*r}{y})}{log(1+r)}.$