Which of the following sequences of numbers are arithmetic sequences?

Check all that apply.

A. 2, 4, 6, 8, 10, ...

B. 1, 1, 1, 1, 1, ...

C. 1, 2, 3, 5, 6, 7, ...

D. 3.0, 3.1, 3.2, 3.3, 3.4, ...

E. 2, - 4, 6, - 8, 10, ...

An arithmetic sequence is a sequence of numbers with a common difference.

In the choices above, only A and D are arithmetic sequences.

In A, the common difference is 2 while in D, it's 0.1.

B can't be an arithmetic sequence since the number 1 is just being repeated many times, there's no progression.

C as well. Be observant of the pattern, it can be an arithmetic sequence only if it has 4 before 5.

E obviously is not an arithmetic sequence. If you try to find the difference between the consecutive terms, it's not common.