PLEASE HELP!


4) The "random walk theory of stock prices holds that price movements in disjoint time periods are independent of each other. Suppose that we record only whether the price is up or down each year, and that the probability that our portfolio rises in price in any one year is 0.65.



a) What is the probability that the portfolio goes up for 3 consecutive years?



b) What is the probability that the portfolio's value moves in the same direction (either up or down) for 3 consecutive years?



c) What is the probability that the portfolio's value goes up for at least 1 of 3 years?​