What is the correct formula to find the sum of the finite geometric series below?

We are given the Geometric Series:

which can be rewritten as:

here, we can see that every term is (1/3) times the last term

Hence, we can say that the common ratio of this Geometric Series is 1/3

Finding the Sum:

We know that the sum of a Geometric Series is:

(where r is the common ratio, a is the first term, and n is the number of terms)

another look at the given Geometric Series tells us that the first term is 2 and the number of terms is 7

plugging these values in the formula, we get:

Sₙ = 2.97

-14 is the answer

hope this : ))