Question

Find the sum of 0.40 + 0.43 + 0.46 + ... + 1

Answer 1

$\textbf{Given:}$

$0.40+0.43+0.46+..............+1$

$\textbf{To find:}$

$\text{Sum of the given A.P series}$

$\textbf{Solution:}$

$\text{Consider}$

$0.40+0.43+0.46+..............+1$

$\text{This is a finite A.P series with a=0.40 and d=0.03 }$

$\textbf{Number of terms in the A.P series}$

$\boxed{\bf\,n=\frac{l-a}{d}+1}$

$n=\dfrac{1-0.40}{0.03}+1$

$n=\dfrac{0.60}{0.03}+1$

$n=\dfrac{60}{3}+1$

$n=20+1$

$\implies\bf\,n=21$

$\textbf{Sum of the n terms of the A.P series}$

$\boxed{\bf\,S_n=\dfrac{n}{2}[a+l]}$

$S_{21}=\dfrac{21}{2}[0.40+1]$

$S_{21}=\dfrac{21}{2}[1.40]$

$S_{21}=21[0.70]$

$\bf\,S_{21}=14.7$

$\therefore\textbf{The sum of 0.40+0.43+0.46+..............+1 is 14.7}$

Find more:

In the AP 7,14,21... how many terms are to be considered for getting sum 5740.

https://brainly.in/question/3171774

The sum of the first 25 terms of ap whose 2nd term is 9 and 4th term is 21

https://brainly.in/question/6158037