Calculating finite geometric series

The  exercise appears under the Precalculus Math Mission. This exercise asks users to calculate finite geometric sequences.

Types of Problems
There two types of problems in this exercise:
 * 1) Find the sum of the n in the geometric sequence: This type of problem gives a geometric series. The user has to find the sum of the n.Sum_geometric.png
 * 2) Find the sum of the first n terms in the geometric sequence with the first term and common ratio: This problem asks the user to Find the sum of the first n terms in the geometric sequence with the first term and common ratio. Geometric.png

Strategies

 * 1) These problems are easy if you know what the formula for the sum of the first n terms of a geometric series is: Formula.png