Question: you pay 5 to play a game where if you...
You pay $5 to play a game where if you roll doubles you win $20 and if you don't roll doubles you win nothing. This means that if you win you earn $15 and if you loose, you earn negative $5.
What are your expected earnings each time you play?
Leave your answer as only a decimal number with 2 decimal places precision (for example 2.45). Do not include a dollar sign.