A Geometric Progression (GP) is a sequence of numbers in which each term after the first is obtained by multiplying the previous term by a constant called the common ratio (\(q\)).
If the first term of the GP is \( a_1 \), then the sequence takes the form:
\[ a_1, a_1q, a_1q^2, a_1q^3, \dots \]
\[ a_n = a_1 q^{n-1} \]
\[ S_n = \frac{a_1(q^n - 1)}{q - 1} \]
\[ S_n = n \cdot a_1 \]
