Question:
In how many ways can three jobs I, II and III be assigned to three persons A, B and C if one person is assigned only one job and all are capable of doing each job?
Solution:
Number of ways of assigning a job to person A = 3
Number of ways of assigning the remaining jobs to person B = 2 (since one job has already been assigned to person A)
The number of ways of assigning the remaining job to person C = 1
Total number of ways of job assignment $=3 \times 2 \times 1=6$