What is the sum of the first 20 terms of the arithmetic sequence shown? \displaystyle \frac{1}{3} 3 1 , \displaystyle \frac{2}

Question

3 years ago

7

{3} 3 2 , 1, \displaystyle \frac{4}{3} 3 4 , \displaystyle \frac{5}{3} 3 5 , ...

1 answer:

Murrr4er [49] · Answer 1 · 2022-07-07T05:04:01+03:00

5 0

Answer:

70

Step-by-step explanation:

$a_1$ = First term = $\dfrac{1}{3}$

$d$ = Common difference = $\dfrac{2}{3}-\dfrac{1}{3}=\dfrac{1}{3}$

$n$ = Number of terms = 20

Sum of arithmetic progression is given by

$S=\dfrac{n}{2}[2a_1+(n-1)d]\\\Rightarrow S=\dfrac{20}{2}\times (2\times \dfrac{1}{3}+(20-1)\dfrac{1}{3})\\\Rightarrow S=70$

The sum of the first 20 terms of the arithmetic sequence is 70.

What is the sum of the first 20 terms of the arithmetic sequence shown? \displaystyle \frac{1}{3} 3 1 ​ , \displaystyle \frac{2}