Math question for this answer

Question

Tickets for a raffle cosr 10. There were 845 tickets sold. One ticket will be randomly selected as the winner, and that person wins 1800 and also the person is given back the cost of the ticket. For someone who buys a ticket, what is the Expected Value (the mean of the distribution)?If the Expected Value is negative, be sure to include the "-" sign with the answer. Express the answer rounded to two decimal places.

Answer 1

The probability of winning is 1/845,

The expectation (which in this case is NOT the mean of the distribution) is (1800/845) + 10 = 12.13, i.e. in the long run this is a raffle in which you should buy a ticket!