Question

Which of the following sequences are in arithmetic progression?

5, 9, 12, 18, .....

Answer 1

5, 9, 12, 18, .....

d₁ = 9 – 5 = 4

d₂ = 12 – 9 = 3

Since d₁ ≠ d₂, the given sequence is not in arithmetic progression.