Help with stats concepts. Help. Statistics overwhelm me.

1. A corporation has four investment possibilities: A, B, and C with respective gains of $10, $20, and $50 million and investment D with a loss of $30 million. If one investment will be made and the probabilities of choosing A, B, C, or D are .1, .4, .2, and .3, respectively, find the expected gain for the corporation.

2.. A marketing research survey shows that approximately 80% of the car owners surveyed indicated that their next car purchase will be either a compact or economy car. Assume the 80% figure is correct and five prospective buyers are interviewed. a. Find the probability that all five indicate that their next car purchase will be either a compact or economy car. b. Find the probability that at most one indicates that her next purchase will be either a compact or economy car.