{"id":8236,"date":"2021-11-17T16:27:44","date_gmt":"2021-11-17T10:57:44","guid":{"rendered":"https:\/\/mathemerize.com\/?p=8236"},"modified":"2021-11-17T16:31:17","modified_gmt":"2021-11-17T11:01:17","slug":"if-the-4th-and-9th-terms-of-a-g-p-be-54-and-13122-respectively-find-the-g-p","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/if-the-4th-and-9th-terms-of-a-g-p-be-54-and-13122-respectively-find-the-g-p\/","title":{"rendered":"If the 4th and 9th terms of a G.P. be 54 and 13122 respectively, find the G.P."},"content":{"rendered":"
Let a be the first term and r the common ratio of the given G.P. Then,<\/p>\n
\\(a_4\\) = 54\u00a0 and\u00a0 \\(a_9\\) = 13122<\/p>\n
\\(\\implies\\)\u00a0 \\(ar^3\\) = 54\u00a0 \u00a0and\u00a0 \\(ar^8\\)\u00a0 =\u00a0 13122<\/p>\n
\\(\\implies\\)\u00a0 \\(ar^8\\over ar^3\\) = \\(13122\\over 54\\)\u00a0 \\(\\implies\\)\u00a0 \\(r^5\\) = 245\u00a0 \\(\\implies\\)\u00a0 r = 3<\/p>\n
Putting r = 3 in \\(ar^3\\) = 54,<\/p>\n
we get a = 2.<\/p>\n
Hence, the given G.P is 2, 6, 18, 54, ….<\/p>\n
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