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Question
For the G.P. if a = `2/3`, t6 = 162, find r.
Solution
Given, a = `2/3`, t6 = 162
tn = arn–1
∴ t6 = `(2/3)("r"^(6 - 1))`
∴ 162 = `2/3"r"^5`
∴ r5 = `162 xx 3/2`
∴ r5 = 35
∴ r = 3
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