What is the sum of the first seven terms of the geometric series?3 + 12 + 48 + 192 + ...

The first term is 3 and each term is multiplied by 4, so the common ratio is 4. The sum of seven terms is 3(4^7 − 1)/(4 − 1) = 4^7 − 1 = 16,383. Therefore, the sum is choice C, 16,383.

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