In an A.P., if the first term a = 7, nth term an 84 and the sum of first n terms = 2093/2, then n is equal to:

STUDY MATERIALS
COURSES
MORE
SUCCESS STORY
ADMISSION
STORE

Back

JEE ADVANCE

CLASS XI - XII
CRASH COURSE

CLASS XI - XII

CRASH COURSE

JEE MAIN

CLASS XI - XII
CRASH COURSE

CLASS XI - XII

CRASH COURSE

NEET

CLASS XI - XII
CRASH COURSE

CLASS XI - XII

CRASH COURSE

BITSAT

CLASS XI - XII

CLASS XI - XII

CBSE BOARD

CLASS IX

CLASS X

CLASS XI

CLASS XII

CLASS VI

CLASS VII

CLASS VIII

UP BOARD

CLASS IX
CLASS X
CLASS XI
CLASS XII

CLASS IX

CLASS X

CLASS XI

CLASS XII

CUET

CRASH COURSE

CRASH COURSE

Courses

CLASSROOM COURSES
ONLINE COURSES

ONLINE COURSES

More

Solution

Q.
In an A.P., if the first term a = 7, nth term an 84 and the sum of first n terms $S_{n}$ = 2093/2, then n is equal to:

1 22

2 24

3 23

4 26

Ans.
(3)

$S_{n} = \frac{n}{2} (a + a_{n}) \Rightarrow \frac{2093}{2} = \frac{n}{2} (7 + 84)$

$\Rightarrow 91 n = 2093 \Rightarrow n = 23$

Want Us to Email you About Special Offers & Updates?