Choose any 6 of the 20 for any one of the 4 jobs =
C(20, 6) * C(4,1) ways
Choose any 4 of the remaining 14 for any of the 3 remaining jobs
C(14, 4) * C(3,1) ways
Choose any 3 of the remaining 10 for either of the 2 remaining jobs
C(10, 3) * C(2,1) ways
[ Note the remaining 7 workers will automatically be assigned to the remaining job ]
So
C(20, 6) * C(4,1) * C(14, 4) * C(3,1) * C(10, 3) * C(2,1) =
111,740,428,800 ways ...... (yikes !!!!)
