The probability mass function, Px(x), of a discrete random variable X is given by:
Px(x) = { x K ; x = 1, 2, 3,.......,10; 0 otherwise
Define event B = "X is even".
a) Determine the value of the constant K.
b) Find E[X] and Var[X].
c) Find PX|B(x), the conditional PMF of X given B. Also determine E[X|B].