SOLUTION: The first term of a geometric series is 3, and the sum of the first term and the second term is 15. What is the sum of the first six terms?

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Question 829923: The first term of a geometric series is 3, and the sum of the first term and the second term is 15. What is the sum of the first six terms?

Answer by reviewermath(1029) About Me  (Show Source):
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Question:
The first term of a geometric series is 3, and the sum of the first term and the second term is 15. What is the sum of the first six terms?
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Answer:
3 + 3r = 15
3r = 12
r = 4
The sum of the first 6 terms is equal to
3 + 12 + 48 + 192 + 768 + 3072 = highlight%284095%29