Question

For each sequence, decide whether it could be arithmetic or geometric or neither. 200, 40, 8

Answer 1

geometric sequence

Explanation:

an arithmetic sequence has a common difference d between consecutive terms.

40 - 200 = - 160

8 - 40 = - 32

no common difference thus not arithmetic

a geometric sequence has a common ratio r between consecutive terms

`(40)/(200)` =
`(4)/(20)` =
`(1)/(5)`

`(8)/(40)` =
`(1)/(5)`

thus there is a common ratio so sequence is geometric