Question

What is the common difference and ninth term for the following sequence:
3,5/2,2,3/2,1

Answer 1

Common Difference:
`-(1)/(2)`

The ninth term: -1

Explanation:

The sequence can be written like this,

3, 2.5, 2, 1.5, 1, ....

Here the common difference is clearly -0.5 or
`-(1)/(2)`, and we can conclude that
`n^(th)` number is
`3 - 0.5(n-1)`. So the 9th term is,

`3 - 0.5(9 - 1)\\= -1`