# How do you determine whether the sequence #80, 40, 20, 10, 5,...# is arithmetic and if it is, what is the common difference?

##### 2 Answers

See explanation.

#### Explanation:

To find if a sequence is arithmwtic, geometric or neither you have to check if either the difference (arithmetic sequence) or quotient (geometric sequence) between any 2 consecutive terms is constant.

**Arithmetic sequence**

**not** arithmetic.

**Geometric sequence**

The quotient of 2 consecutive terms is constant

No.. its not

#### Explanation:

The sequence

And, their common ratio is

Therefore this sequence is **geometric** .

It would be **arithmetic** if the next term was formed by addition or subtraction.