Select ALL of the following which are examples of an arithmetic sequence.

6, 11, 15, 21, 26, 30
6, 11, 15, 21, 26, 30

12, 9, 6, 3, 0, −3
12, 9, 6, 3, 0, −3

You start at an elevation of 15,000 feet and climb down 2,000 feet per day.
You start at an elevation of 15,000 feet and climb down 2,000 feet per day.

−2, −4, −8, −16, −32
−2, −4, −8, −16, −32

You add $1 to a piggy bank and add double the money you added the previous day for one month.