Find the 8 th term of a G.P., if its common ratio is 2 and 10 th term is 768.

Given, Common ratio (r) = 2 By formula, ⇒ a n = ar n - 1 Given, 10 th term of G.P. = 768 ⇒ a 10 = 768 ⇒ ar 10 - 1 = 768 ⇒ ar 9 = 768 ⇒ a × 2 9 = 768 ⇒ a × 512 = 768 ⇒ a = . 8th term of G.P. is given by : ⇒ a 8 = ar 8 - 1 ⇒ a 8 = ar 7 ⇒ a 8 = ⇒ a 8 = 3 × 2 6 ⇒ a 8 = 3 × 64 = 192. Hence, 8 th term of a G.P. is given by 192.