Fourth and seventh terms of a G.P. are 1/18 and -1/486 respectively. Find the G.P.

Let first term of the G.P. be a and it's common ratio be r. Given, ⇒ a 4 = ⇒ ar 3 = ........(i) Also, ⇒ a 7 = ⇒ ar 6 = ........(ii) Dividing (ii) by (i) we get, Substituting value of r in (i) we get, ⇒ a 2 = ar = = . ⇒ a 3 = ar 2 = = = G.P. = Hence, G.P. =