Question

The sum of first 10 terms of the G.P 3, 6, 12, 24,... is .

• A. 3500
• B. 3069
• C. 2059
• D. 4079

Answer 1

The correct option is B 3069

First term, $a=3$

Common ratio, $r=2$

Sum of $n$ terms, $S_n=\frac{a(r^n-1)}{r-1}$

$\Rightarrow S_{10}=\frac{a(r^{10}-1)}{r-1}$

$=\frac{3(2^{10}-1)}{2-1}$

$=(1024-1)\times 3=3069$