11, 8, 5, 2, . . . In this A.P. which term is number – 151?

By, given A.P. 11, 8, 5, 2, . . .
we have a = 11, t₁ = 8, t₂ = 5
Thus, d = t₂ – t₁ = 5 – 8 = – 3
Given t_n = – 151
Now, by using n^th term of an A.P. formula t_n = a + (n – 1) d
we can find value of “n”
Thus, on substituting all the value in formula we get,
– 151 = 11 + (n – 1) × (– 3)
⇒ – 151 – 11 = (n – 1) × (– 3)
⇒ – 162 = (n – 1) × (– 3)
⇒ n – 1 = -162/-3 = 54
⇒ n = 54 + 1 = 55