+1 vote
in General by kratos

For the following G.P.*, find Sn

0.7, 0.07, 0.007, .....

1 Answer

+6 votes
by kratos
 
Best answer

a = 0.7 = $7/10$, r = $0.07/0.7 = 1/10 < 1$

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

= $(7/10[1 - (1/10)^"n"])/(1 - 1/10)$

= $7/9 (1 - 1/10^"n")$

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