## If the 4th and 9th terms of a G.P. be 54 and 13122 respectively, find the G.P.

Solution : Let a be the first term and r the common ratio of the given G.P. Then, \(a_4\) = 54 and \(a_9\) = 13122 \(\implies\) \(ar^3\) = 54 and \(ar^8\) = 13122 \(\implies\) \(ar^8\over ar^3\) = \(13122\over 54\) \(\implies\) \(r^5\) = 245 \(\implies\) r = 3 Putting r = 3 in \(ar^3\) = 54, …

If the 4th and 9th terms of a G.P. be 54 and 13122 respectively, find the G.P. Read More »