A fair die is rolled once, and the number score is noted. Let the random variable X be twice this score, and define the variable Y to be one if an odd number appeared and three if an even number arose. By finding the probability mass function in each case, find the expectation of the following random variables:

Please answer to 3 decimal places.

Part a) $X$


Part b) $Y$


Part c) $X+Y$


Part d) $XY$