Answer:
16373
Explanation:
Pre-Solving
We are given the following geometric series:
3, 12, 48, 192....
And we want to find the sum of 7 terms.
The sum of n number of terms in a geometric series is
, where
is the first term, r is the common ratio, and n is the number of terms being added.
To get the common ratio, we can divide
; as we already know,
is the first term, which is 3.
is the second term, which is 12.
So, the common ratio is 12/3 = 4
Since we are finding the sum of the first seven terms, n = 7.
Solving
We can plug what we know into the formula.

Plug the above into a calculator.

So, the sum is 16383.