Need help with following probability question:

Problem 3. (30 points) Let X be a random variable with momentgenerating function 1 1 1 ir(t) : g + get + 36%. a) Find the mean and variance of X } using the derivates of 1M (t) b) Find the pmf of X. Hint: Use the result from question 2, and recall that the mgf of a Bernoullio) random variable is MOS) = (1 *3?) +1069