Question

1, 6, 11, 16 ...... Find the 18^th term of this A.P.

Answer 1

The given A.P. is 1, 6, 11, 16, ......

Here, a = 1, d = 6 – 1 = 5

Since t_n = a + (n – 1)d,

t₁₈ = 1 + (18 – 1)(5)

= 1 + 17(5)

= 1 + 85

= 86

∴ 18^th term of the given A.P. is 86.