Find whether 55 is a term of the AP: 7, 10, 13, ______or not. If yes, find which term it is.
Let 55 is the nth term of an AP
Given AP is 7, 10, 13........
Here a = 7, d = 10 - 7
d = 3
By equation (1) is
Here n is a positive integer.
Hence 55 is 17th term of an AP