Question

Find 27^th and n^th term of given A.P. 5, 2, – 1, – 4, ......

Answer 1

The given A.P. is 5, 2, – 1, – 4, ......

Here, a = 5, d = 2 – 5 = – 3

Since t_n = a + (n – 1)d,

t_n = 5 + (n – 1)(– 3)

∴ t_n = 5 – 3n + 3

∴ t_n = 8 – 3n

∴ t₂₇ = 8 – 3(27)

= 8 – 81

= – 73

∴ n^th term of the given A.P. is 8 – 3n and 27^th term is – 73.