Q. The   sum of the first n terms of the series 
12 + 2.22 + 32 + 2.42 +52 + 2.62 + .... is  n ( n   +   1 ) 2 2  , when  n is even. When n is odd , the sum is 
(A)  n 2 ( n + 1 ) 2               (B)  n   ( n   +   1 ) ( 2 n +   1 ) 6             (C)  n ( n   +   1 ) 2 2   (D)  n 2 ( n   +   1 ) 2 2

  • 2
Ans b
  • 1
Please Refer ncert Ex Q.2.Same model
  • 0
Anyway option b
  • 0
What are you looking for?