Which person should be assigned to which job? How long will the jobs take? There are 4 jobs in a ...

Which person should be assigned to which job? How long will the jobs take?
 
  There are 4 jobs in a 4 person office that must be done as quickly as possible. The supervisor has used the assignment method to assign people to jobs, and has completed the first step. She had to rush off to a meeting and has asked to assign the jobs to the people before she returns. The original matrix which shows the expected completion time for each person for each job, and the one she just completed are both shown below.
 
  Job Ruth Steve Valerie Wayne
  A 8 26 17 11
  B 13 28 4 26
  C 38 19 18 15
  D 19 26 24 10
 
  Job Ruth Steve Valerie Wayne
  A 0 18 9 3
  B 9 24 0 22
  C 23 4 3 0
  D 9 16 14 0