probability question

Question

1000 tickets are sold for a charity lottery at $5 each. Three numbers are drawn at random to receive 1st 2nd and 3rd place prizes of $2000, $1000, and $500 respectively. what is the mean (expectation) from such a drawing?

Answer 1

2000/1000+ 1000/1000+ 500/1000 = 2+1+.5= $3.50 pay off expected

but subtract cost of playing of $5

expected "winnings" are 3.5-5= a

$1.50 loss per ticket purchased

and $1,50 per ticket goes to the charity