You plan to invest $200,000 in stocks on the Toronto Stock Exchange. If you invest $2000 in any particular stock, your profit will be $400, $200, $0 or -$200 (a loss) with probability 0.25 each. There are 100 different stocks you can choose from, and they all behave independently of each other.
a) If you invest $200,000 in one stock, what is the probability that your profit will be $15,000 or more.
b) If you invest $2000 in each of the 100 stocks, what is the probability that your profit will be $15,000 or more.