Find the number of term in the Arithmetic Progression(A.P) 2, -9, -20,…-141.

Find the number of term in the Arithmetic Progression(A.P) 2, -9, -20,…-141.

Correct Answer: Option D

Explanation

T₁, T₂, T₃
2, -9, -20 …. -141
l = a + (n – 1)d
first term, a = 2
common difference d = T₃ – T₂
= T₂ – T₁
= -20 – (-9) = -9 -2
= -20 + 9
= -9 -2
= -20 + 9
= -11
-11 = -11
d = -1
last term l = -141
-141 = 2 + ((cap) – 1) (-11)
-141 = 2 + (-11 (cap) + 11)
= 2 – 11(cap) + 11
-141 = 13 – 11(cap)
-141 – 13 = -11(cap)
-154 = -11(cap)
(cap) = (frac{-154}{-11})
(cap) = 14