Question

Which of the following is an arithmetic sequence?

Answer 1

An arithmetic sequence is a sequence of numbers wherein the difference between any two consecutive terms is the same.

The only arrangement that happens to be an arithmetic sequence is:

$19,11,3,–5,–13,–21$

Let us consider the other options.

$\underset{–}{1,–1,1,–1,1,–1,...}$
$(–1)–\left(1\right)=–2$ and $1–(–1)=2$
Since $–2\ne 2,$ this arrangement is not an arithmetic sequence.

$\underset{–}{37,48,59,71,82,93,...}$
$59–48=11$ and $71–59=12$
Since $11\ne 12,$ this arrangement is also not an arithmetic sequence.

$\underset{–}{2,4,8,16,32,64,...}$
$4–2=2$ and $8–4=4$
Since $2\ne 4,$ this arrangement is not an arithmetic sequence.