The carnival operator is creating the new game.
In this game, player will place the bet. Then the ball is selecteded from the urn having balls of 3 colours: 2 green balls, 4 red balls and 7 white balls.
If the red ball is drawn, player wins 3$, if the green ball is drawn, player wins 4$, and if the white ball is drawn player wins nothing.
What must carnival operator set bet at if on average he makes $0.50 profit a game?