A sequence of numbers {N_{n}} is called a geometric series if N_{n+1} = N_{n} ∙ d or N_{n} = N_{0} ∙ d^{n}. The q is called a geometric ratio. A bank deposit is an example of a geometric series. A bank rate r gives a geometric ratio d = r+1. A deposit at a nth month is N_{n} = N_{n1} ∙ d or N_{n} = N_{0} ∙ d^{n}. A sum of n first members of the sequence S_{n} = N_{0} ∙ (d^{n}1)/(d1) if d is not equal to 1 and S_{n} = N_{0}nd if d=1. This model demonstrates a solution for 2 types of problems. In the first, a bank rate, start deposit and a time period are given and a deposit at given period is calculated. Otherwise a start deposit is calculated depend on deposit at given period and bank rate. You can also solve suggested problems and check you answers. Choose the Solve the problem radio button and a type of problem, insert the answer into the Answer spinbox and click the check button. If you want to see a solution of the problem click the solution button. You cannot change the problem specification in solving mode, but only in demonstration mode. To work with a different problem click the next button.
