Question

For the following G.P.*, find Sn

3, 6, 12, 24, ...

Answer 1

3, 6, 12, 24,

Here, a = 3, r = $6/3$ = 2 > 1

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

Sn = $(3(2^"n" - 1))/(2 - 1)$

Sn = 3(2n 1)