Evaluate $\sum\limits_{k = 1}^{11} {\left( {2 + {3^k}} \right)} $

Vedclass pdf generator app on play store
Vedclass iOS app on app store
We need to evaluate the sum $\sum\limits_{k = 1}^{11} {\left( {2 + {3^k}} \right)}$.
Using the linearity property of summation,we have:
$\sum\limits_{k = 1}^{11} {\left( {2 + {3^k}} \right) = } \sum\limits_{k = 1}^{11} {2 + } \sum\limits_{k = 1}^{11} {{3^k}} = 2 \times 11 + \sum\limits_{k = 1}^{11} {{3^k}} = 22 + \sum\limits_{k = 1}^{11} {{3^k}} \quad \dots (1)$
The sum $\sum\limits_{k = 1}^{11} {{3^k}}$ is a geometric series with first term $a = 3$,common ratio $r = 3$,and number of terms $n = 11$.
The sum of a geometric series is given by $S_n = \frac{a(r^n - 1)}{r - 1}$.
Substituting the values,we get:
$S_{11} = \frac{3(3^{11} - 1)}{3 - 1} = \frac{3}{2}(3^{11} - 1)$.
Substituting this back into equation $(1)$:
$\sum\limits_{k = 1}^{11} {\left( {2 + {3^k}} \right) = 22 + \frac{3}{2}(3^{11} - 1)}$.

Explore More

Similar Questions

If three numbers are in a geometric progression,then their logarithms are in:

In a geometric progression consisting of positive terms,each term equals the sum of the next two terms. Then the common ratio of its progression is equal to:

Let $a_1, a_2, a_3, \ldots$ be a $G.P.$ of increasing positive terms. If $a_1 a_5 = 28$ and $a_2 + a_4 = 29$,then $a_6$ is equal to

If $a_1, a_2, a_3, \ldots, a_{10}$ is a geometric progression and $\frac{a_3}{a_1}=25$,then $\frac{a_9}{a_5}$ equals

In an increasing geometric series,the sum of the second and the sixth term is $\frac{25}{2}$ and the product of the third and fifth term is $25$. Then,the sum of the $4^{\text{th}}$,$6^{\text{th}}$,and $8^{\text{th}}$ terms is equal to

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo