alleryHow many terms of the G.P. 3, 3/2, 3/4, … are needed to give the sum 3069/512?
A8
B9
C10
D11
Answer & Solution
Correct answer: C. 10
a=3, r=1/2; 3(1−1/2^n)/(1/2) = 6(1−1/2^n) = 3069/512 ⇒ 1/2^n = 1/1024 ⇒ n=10.
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