This is the Important question based on Arithmetic progression Chapter of R.S Aggarwal book for ICSE & CBSE Board.
In this Question you have to find the sum upto n terms.
This is the Question Number 32 Of Exercise 11 C of RS Aggarwal Solution
Deepak BoraNewbie
Find the sum of the following : (1-1/n)+(1-2/n)+(1-3/n)+……upto n terms.
Share
According to the Question:
a=1-1/n
a=(n-1)/n
d=1-2/n-1+1/n
d=1/n
Sum
=n/2(2a+(n-1)d)
=n/2[2(n-1)/n+(n-1)-1/n]
=n/2{[2(n-1)-(n-1)]/n]}
=n/2[(n-1)/n]
=1/2(n-1)