Question

Which of the following is not a geometric sequence?

• A. $2,4,8,16, \ldots$.
• B. $\frac{1}{9}, \frac{-1}{27}, \frac{1}{81}, \frac{-1}{243}, \ldots \ldots$
• C. $0.01,0001,000001 \ldots \ldots$
• D. None of these

Answer 1

Answer: (D)

$2,4,8,16, \ldots$ is a geometric sequence with common ratio 2 .
$\frac{1}{9}, \frac{-1}{27}, \frac{1}{81}, \frac{-1}{243}, \ldots$ is a geometric sequence with common ratio $\frac{-1}{3}$
$.01, .0001, .000001$, common ratio 01 .
is a geometric sequence with
Hence, (a), (b) and (c) are the examples of geometric sequence.