In which of the following series can be the formula S = \(\frac{a}{1 – r}\) where a is the first term and r is the common ratio, be used to find the sum of all the terms?
- 4 + 8 + 16 + 32 + ...
- \(\frac{1}{2}\) + 2 \(\frac{1}{2}\) + 12\(\frac{1}{2}\) + 62 \(\frac{1}{2}\) + ..
- \(\frac{4}{81}\) + \(\frac{2}{27}\) + \(\frac{1}{9}\) + \(\frac{1}{6}\) + ...
-
128 + 64 + 32 + 16 + ...
