Question
Evaluate the following:$\sum_\limits{\text{n}=1}^{11}(2+3^\text{n})$

Answer

$\sum_\limits{\text{n}=1}^{11}(2+3^\text{n})$ $=(2+3^1)+(2+3^2)+(2+3^3)+\ \dots\ +(2+3^{11})$ $=2\times11+3^1+3^2+3^3+\dots+3^{11}$ $=22+\frac{3(3^{11}-1)}{(3-1)}$ $=22+\frac{3(3^{11}-1)}{2}$ $=\frac{44+3(177147-1)}{2}$ $=\frac{44+3(177146)}{2}$ $=265741$ So, $\sum_\limits{\text{n}=1}^{11}(2+3^\text{n})=265741$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Evaluate the following one sided limits: $\lim\limits_{\text{x}\rightarrow-2^+}\frac{\text{x}^2-1}{2\text{x}+4}$
Find the mean and variance of the following data.
$x_i$ 92 93 97 98 102 104 109
$f_i$ 3 2 3 2 6 3 3
A man wants to cut three lengths from a single piece of board of length 91cm. The second length is to be 3cm longer than the shortest and the third length is to be twice as long as the shortest. What are the possible lengths of the shortest board if the third piece is to be at least 5cm longer than the second?
[Hint: If x is the length of the shortest board, then x , (x + 3) and 2x are the lengths of the second and third piece, respectively. Thus, x + (x + 3) + 2x $\leq$ 91 and 2x $\ge$ (x + 3) + 5].
A dice is thrown twice. What is the probability that at least one of the two throws come up with the number 3?
Find all pairs of consecutive odd natural number, both of which are larger than 10, such that their sum is less than 40.
Find the mean deviation about the mean for the following data:
12, 3, 18, 17, 4, 9, 17, 19, 20, 15, 8, 17, 2, 3, 16, 11, 3, 1, 0, 5
Find the sum of the following series to infinit:$\frac{1}{3}+\frac{1}{5^2}+\frac{1}{3^3}+\frac{1}{5^4}+\frac{1}{3^5}+\frac{1}{5^6}+\ ...\infty$
If $\text{z}_1=2-\text{i}, \ \text{z}_2=-2+\text{i},$ Find $\text{Im}\Big(\frac{1}{\text{z}_1\bar{\text{z}}_1}\Big)$
Find the sum of integers from 1 to 100 that are divisible by 2 or 5.
In how many ways can the letters of the word 'STRANGE' be arranged so that.
  1. The vowels come together?
  2. The vowels never come together? and
  3. The vowels occupy only the odd places?