The president of a consulting firm wants to minimize the total number of hours it will take to complete four projects for a new client. Accordingly, she has estimated the time it should take for each of her top consultants-Charlie, Gerald, Johnny, and Rick-to complete any of the four projects, as follows: Project (Hours)
Consultant A B C D
Charlie 13 16 11 13
Betty 11 15 14 18
Johnny 15 22 12 15
Rick 17 17 12 22

Required:
a. In how many different ways can she assign these consultants to these projects?
b. What is the optimal assignment of consultants to projects?
c. For the optimal schedule, what is the total number of hours it will take these consultants to complete these projects?