Hello please need help with this question below

Question 1: The probability mass function of the possible outcomes of an unfair (non-uniform) die is given in the following table: a 2 3 4 5 6 p(a) 1/12 2/12 3/12 3/12 2/12 1/12 a) Determine and sketch its cumulative probability distribution function F(a). (9 pts) b) A new discrete random variable is defined as the sum of two rolls of this die. That is, B=A1+A2, where A1 and A2 are the random variables representing the first two rolls. Determine the probability mass function of B. (9 pts)