The first three elements of an arithmetic sequence are 20,16, and 12. Which element is -96?

### 1 Answer | Add Yours

The nth term of an arithmetic series is given by Tn = a + (n - 1)d, where a is the first term and d is the common difference.

The first three terms of the series you have given are 20, 16 and 12. The first term of the series is 20, a = 20 and the common difference is 16 - 20 = 12 - 16 = -4

If -96 is the nth term: -96 = 20 - (n - 1)*4

=> n - 1 = (96 + 20)/4 = 29

=> n = 30

**The 30th term of the series is -96**

### Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes