Question

Given the sequence below determine the 15th term.

14, 11, 8, 5, ...

Answer 1

- 28

Explanation:

There is a common difference d between consecutive terms, that is

d = 11 - 14 = 8 - 11 = 5 - 8 = - 3

This indicates the sequence is arithmetic with n th term

`a_(n)` = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Here a₁ = 14 and d = - 3 , thus

`a_(15)` = 14 + (14 × - 3) = 14 - 42 = - 28