In a modified mahjong game, the chance to win is 10% where you will win $8 and if you lose which is 90% chance, you will need to pay $1. Outcome of each trial/round is independent of all other trials/rounds.

1. Suppose you have planned to play 10 rounds, and Y denote the number of rounds out of 10 that you won, your net winnings is defined as X = A1+A2+...+A10, find the variance of the random variable W as in V(W).