Find the Expected value

Question

A fundraising raffle where they sold 3994 tickets for 5$ each. There was one first-place prize worth 852$ and 5 second place prizes each worth 20$. What is the Expected value?

Answer 1

3994 at $5 per ticket

1st prize: $852

5 2nd prizes: $20

expected value = 852(1/3994) + 20(5/3994) - 5(3988/3994)

= .about .213+.025 -4.992

= .238-4.992 = -4.754

expected value of buying a ticket = a loss of about $4.75