Question

Find n if the nth term of the following A.P. is 68

5, 8, 11, 14, ..........

Answer 1

Given that

a = 5, d = 3, `t_n = 68`

`t_n = a + (n-1)d`

68 = 5 + (n -1)3

63 = (n-1)3

n -1 = 21 ⇒ n = 22