You buy $10 raffle ticket for a new car valued at $15,000. 2000 tickets are sold. What is expected value of your gain?

So your gains are given by:
[tex]\text{gains}=\text{price of the car}-\text{price of the ticket}[/tex]Then we get:
[tex]\text{gains}=\text{\$}15000-\text{\$}10=\text{\$}14990[/tex]And that's the value of your gain.