What are the expected winnings for a person buying one ticket?

Question

A raffle offers a first prize of $1000, 2 second prizes of $300, and 20 third prizes of $10 each. If 10000 tickets are sold at 25 cents each, find the expected winnings for a person buying 1 ticket

Answer 1

1000(1/10,000) + 300(1/5000) + 10(1/500)

1/10 + 3/50 + 1/50

5/50 + 3/50 + 1/50

10/50

1/5

 

20 cents