Question

Let SK = $\frac{1+2+...+ K}{K}$ and $\displaystyle\sum_{j=1}^{n}S_j^2=\frac{n}{A}(Bn^2+Cn+D)$, where A,B,C,D∈N and A has least value. Then

• A. A+B+C+D is divisible by 5
• B. A+B is divisible by D
• C. A+B=5(D-C)
• D. A+C+D is not divisible by B

Answer 1

Answer: (B)

A+B is divisible by D

Answer 2

The correct option is(B): A+B is divisible by D