Question

If k, 2k- 1 and 2k + 1 are three consecutive terms of an A.P., the value of k is

(A) 2

(B) 3

(C) -3

(D) 5

Answer 1

Correct answer: B
k, 2k - 1, 2k + 1 are in Arithmetic Progression
if a₁, a₂ and a₃ are in A.P. then
a₂ –a₁ = a₃ – a₂
2a₂ = a₃ + a₁
2 x (2k - 1) = (2k +1) + k
4k - 2 = 3k +1
k = 3