Six stand-up comics, a, b, c, d, e, and f, are to perform on a single evening at a comedy club. the order of performance is determined by random selection. find the probability that: a. comic upper b will perform fourth. b. comic upper c will perform second and comic upper e will perform third. c. the comedians will perform in the following order: upper b comma upper c comma upper e comma upper d comma upper f comma upper a. d. comic upper f or comic upper a will perform second.