Examveda
Examveda

The common difference of an A.P., the sum of whose n terms is Sn, is

A. Sn - 2Sn - 1 + Sn - 2

B. Sn - 2Sn - 1 - Sn - 2

C. Sn - Sn - 2

D. Sn - Sn - 1

Answer: Option A

Solution(By Examveda Team)

Sum of n terms = Sn
∴ an = Sn - Sn - 1
and an - 1 = Sn - 1 - Sn - 2
∴ Common difference (d) = an - an - 1
= (Sn - Sn - 1) - (Sn - 1 - Sn - 2)
Sn - Sn - 1 - Sn - 1 + Sn - 2
= Sn - 2Sn - 1 + Sn - 2

This Question Belongs to Arithmetic Ability >> Progressions

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