যোগফল কত ? 22+42+62 ........ +(2n)2 = ?
A
23n(n-1)(n-1)
B
23n(n+1)(2n+1)
C
23n(n-1)(2n+1)
D
23n(n-1)(2n-1)
Correct Answer: 23n(n+1)(2n+1)
