Find the sum of the infinite G.P. 16, 8, 4, ...
Answer: A
The first term \(a = 16\) and the common ratio \(r = 8/16 = 1/2\). The sum of an infinite G.P. is given by \(S_\infty = \frac{a}{1-r}\), provided \(|r| < 1\). Here, \(|1/2| < 1\), so the sum exists. \(S_\infty = \frac{16}{1 - 1/2} = \frac{16}{1/2} = 32\).