Which of the following are APs? If they form an AP, find the common difference d and write three more terms.
12, 32, 52, 72,.......
a2 – a1 = 32 – 12 = 9 – 1 = 8
a3 – a2 = 52 – 32 = 25 – 9 = 16
As a2 – a1 ≠ a3 – a2, the given list of numbers does not form an A .P.