Question

The sum of 10 terms of GP $\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\dots \dots \dots \dots$. is

• A. $\frac{2^{10}-1}{2^{10}}$
• B. $\frac{2^9-1}{2^9}$
• C. $\frac{2^{10}-1}{2^9}$
• D. $\frac{2^9-1}{2^{10}}$

Answer 1

Answer: (A)

$a=1/2$ and $r=1/2$
$\Rightarrow S_{10}=\frac{1}{2}\frac{{\left(1-\frac{1}{2}\right)}^{10}}{1-\frac{1}{2}}=\frac{2^{10}-1}{2^{10}}$