Check whether -150 is a term of the AP : 11, 8, 5, 2 …….

In the A.P. : 11, 8, 5, 2 …….

First term (a) = 11 and common difference (d) = 8 - 11 = -3.

Let -150 be nth term of the A.P.

By formula,

a_n = a + (n - 1)d

Substituting values we get :

⇒ -150 = 11 + (n - 1) × -3

⇒ -150 = 11 - 3n + 3

⇒ 3n = 150 + 11 + 3

⇒ 3n = 164

⇒ n = $\dfrac{164}{3} = 54\dfrac{2}{3}$.

Since, number of term cannot be in fraction.

Hence, -150 cannot be the term of the A.P.