Hi there

You should consider each prize and the probability of recieving thast prize.

For $25: probabilty = 12,000/3,000,000

For $10,000: probabilty = 4/3,000,000

For $50,000: probabilty = 1/3,000,000

For $200,000: probabilty = 1/3,000,000

and finally if you don't win the prize is $-1 so

For $-1: probabilty = (3,000,000-12,006)/3,000,000 = 2,987,994/3,000,000

Now multiply each return by its respective probabilty and sum the products together. This is the expected value.