Suppose X and Y are random variables for which Var(X)=5 and Var(Y)=3. Find Var(3X 2Y). Identify which of the following variables can be described by a binomial random variable. (a) Number of phone calls during an hour. (b) Number of coin tosses until heads occurs. (c) Number of correct answers on a multiple choice test with 20 questions when guessing and there are 5 choices for each question. (d) Number of people that are red-green color blind in a random selection of 100 people.