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

Question

Philoid · Accepted Answer

Given first term (a) = 18

Common difference (d) = n₂-n₁ = 8 – 11 = -3

Let us consider -150 is a term in above series.

Then, a_n = -150

a_n = a + (n-1)d

-150 = 11 + (n-1)(-3)

-161 = (n-1)(-3)

n-1 =

n =

Since n is not an integer the given number is not in the series.