Question

If the sum of n terms of a progression is given by $n{}^2+n$, then the progression is called

• A. Arithmetic progression
• B. Geometric Progression
• C. Harmonic Progression
• D. None of these

Answer 1

The correct option is A

Arithmetic progression

Let $S_n$ and $S_{(n-1)}$ denote the sum of first n and (n-1) terms respectively of the progression,then the n^th term of the progression is given by =$S_n-S_{(n-1)}=2n$

Common difference between two consecutive terms of the progression will be 2, then the progression is Arithmetic progression