Question

First term and common difference of an A.P. are 12 and 4 respectively. If t_n = 96 find n.

Answer 1

Given, first term = 12, common difference = 4 and t_n = 96.

According to the formula,

t_n = a + (n – 1) d

∵ t_n = 96

∴ 96 = 12 + (n – 1) 4

⇒ 96 = 12 + 4n – 4

⇒ 96 = 8 + 4n

⇒ 4n = 96 – 8

⇒ 4n = 88

⇒ n = `88/4`

∴ n = 22