JEE Main PAPER - 1

Let A be the sum of the first 20 terms and B be the sum of the first 40 terms of the series $1^2 + 2 \cdot 2^2 + 3^2 + 2 \cdot 4^2 + 5^2 + 2 \cdot 6^2 + \dots$  . If $B - 2A = 100\lambda$  , then $\lambda$   is equal to: