Go To Your Study Dashboard

Get Answers to all your Questions

header-bg

Q : 3 In an AP:

(i) given $\small a=5$ , $\small d=3$ , $\small a_n=50$ , find $\small n$ and $\small S_n$ .

Answers (1)

best_answer

It is given that
$a = 5, d = 3 \ and \ a_n = 50$
Let suppose there are n terms in the AP
Now, we know that
$a_n = a+(n-1)d$
$\Rightarrow 50 = 5 + (n-1)3$
$\Rightarrow 48 = 3n$
$\Rightarrow n = 16$
Now, we know that
$S = \frac{n}{2}\left \{ 2a+(n-1)d \right \}$
$\Rightarrow S = \frac{16}{2}\left \{ 2\times(5) +(16-1)(3)\right \}$
$\Rightarrow S = 8\left \{ 10+45\right \}$
$\Rightarrow S = 8\left \{ 55\right \}$
$\Rightarrow S =440$
Therefore, the sum of the given AP is 440

Posted by

Gautam harsolia

View full answer

Similar Questions

Trending Articles/News

anam-khan

CBSE Board Exam 2026: Two exams for Class 10 ‘exhausting’ for teachers, cause more anxiety for students

anam-khan

Board Exams 2026: NCERT PARAKH forms expert committee to standardise Class 10, 12 certificates

Latest Question