A set of 10 cards consists of 10 card with "$" and 1 card with "STOP". In this game, if the man draw a card with "$", he can get $1 dollar and the he place the card back to the set. The game will stop when he draw the "STOP" card. (a) What is the probability of getting a "STOP" card? (b) What is the mean of getting a "STOP" card? (c) If we add 5 more "STOP" card to the set, what is the probability of the man win 3 dollars from the game? d) If the game with 15 card setting is required $3 to join, is it attractive to you?