Is 0 a term of the AP 31, 28, 25,…?

Let 0 be the nth term of given AP i.e., an = 0.

Given that, first term a = 31, common difference, d = 28 – 31 = – 3

The nth terms of an AP, is

$a_{n}=a+(n-1) d$

$\Rightarrow \quad 0=31+(n-1)(-3)$

$\Rightarrow \quad 3(n-1)=31$

$\Rightarrow \quad n-1=\frac{31}{2}$

$\therefore$ $n=\frac{31}{3}+1=\frac{34}{3}=11 \frac{1}{3}$

Since, n should be positive integer. So, 0 is not a term of the given AP.