A student invests on three risky projects. He will spend $100 on each project. Let S1, S2 and S3 be the events that the first, second and third project respectively return some money. Suppose all events are mutually independent and 1=(1)=0.2 and 1 returns $1000, 2=(2)=0.3 and 2 returns $500, 3=(3)=0.6 and 3 returns $200. Let be the random variable that represents the student's net returns in dollars.

Calculate the possible values for and the corresponding probabilities

What is the expected value of the winnings, [] ?