Question

The sum of first 3 terms of a G.P is 16 and the sum of next 3 terms is 128. Find the sum of n terms of the G.P?

• A. $\frac{\left(16\right(2^n+1\left)\right)}{7}$
  
• B. $\frac{\left(16\right(2^n-1\left)\right)}{7}$
  
• C. $\frac{\left(9\right(3^n-1\left)\right)}{7}$
  
• D. $\frac{\left(16\right(3^n-1\left)\right)}{7}$
  

Answer 1

The correct option is B $\frac{\left(16\right(2^n-1\left)\right)}{7}$


Option B is the correct answer. Check the video for the approach.