Adv
Rajan@2021
  • 0
Guru

Find the sum of the following arithmetic series: 7 + 10 1/2 + 14 +….+ 84.

  • 0

A basic and conceptual question from arithmetic progression chapter in which we are to find the sum of the given arithmetic series

7 + 10 1/2 + 14 +….+ 84.

RS Aggarwal, Class 10, chapter 5C, question no 2(i).

Share

1 Answer

  1. In given series of AP first term a=7, common difference d= 10217=2217=27 and last term l=84
    Since, l=a+(n1)d
    84=7+(n1)27
    847=(n1)27
    77=(n1)27
    77×72=n1
    22=n1
    n=23
    Since, Sn=n​/2(a+l)
    Sn=23/2(7+84)
    Sn=91×23/2
    Sn=2093/2
    Sn=1046 1/2

    • 0
Leave an answer

Leave an answer

Browse

Choose from here the video type.

Put Video ID here: https://www.youtube.com/watch?v=sdUUx5FdySs Ex: "sdUUx5FdySs".

Captcha Click on image to update the captcha.

Related Questions