When a deposit is made for several years and rates are included to the capital, the rate is calculated with [color=#0000ff]compound interest[/color]:[br][br][math]\large \textcolor{blue}{C(n)=C\cdot q^n},[/math][br][br]where[br][br][color=#0000ff]C [/color]= capital[br][color=#0000ff]C(n) [/color]= increased capital[br][color=#0000ff]n [/color]= number of interest time, e.g. years[br][color=#0000ff]q [/color]= rate factor [math] 1+\frac{i}{100}[/math]

A person deposits 2100€ for an account for 6 years. Interest rate is 2.1% p.a. How much money is in the account at the end, if no money is withdrawn during the deposit time?[br][br]C = 2100€[br]n = 6[br]i = 2.1% p.a.[br]q= [math] 1+\frac{2.1}{100}[/math]=1.021[br][br][math] C(6) =2100€\cdot 1.021^6=2378.89€[/math]