19)In a G.P. 729, 243, 81,... find \(t_7\)
Answer: \(n^{th}\) term of G.P = \(ar^{n-1}\)
Here a = 729
\(r = \frac{t_2}{t_1} = \frac{243}{729} = \frac{1}{3}\)
\(t_7 = ar^{7-1} = ar^6 = 729 \left(\frac{1}{3}\right)^6\)
\(= 729 \times \frac{1}{729} = 1\)
\(t_7 = 1\)