# For the following G.P.'*, find Sn: 3, 6, 12, 24, ...

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For the following G.P.'*, find Sn: 3, 6, 12, 24, ...

Here, a = 3, r = $6/3$ = 2 > 1
Sn = $("a"("r"^"n" - 1))/("r" - 1)$, for r > 1
Sn = $(3(2^"n" - 1))/(2 - 1)$