SQL & PL/SQL :: Linking Table Challenge - Showing A Value Only Once Not For Each Match?

TABLE 1 : COSTS

I have a table of Costs. We have Jobs that run and there will be a cost associated with a particular machine.So JobNo 1 may run on Machine A and have a cost of 50 dollars. Although its now shown below JobNO 1 could run on MachineB and so on.

JOBNO MACHINE COST
1 MachineA 50
2 MachineA 70
3 MachineA 100

TABLE 2: OPERATIONS

We have operators (PERSONCODE) run the jobs on the machines. So Job 1 may be run by PERSONCODE 8 (e.g. Tony) and it may run on MachineA or MachineB.Multipe people may run a particular job. The PERSONCODE will be unique to the Job and it is actually unique to the list. A person never works on more than one job.

JOBNO MACHINE PERSONCODE
1 MachineA8
1 MachineA7
1 MachineB6
2 MachineA3
2 MachineA2
2 MachineA1
3 MachineA4

DESIRED RESULT:

I need to assign the COSTs to the OPERATIONS table but only want it to show next to one person (next to the appropriate machine).

DESIRED RESULT:

JOBNO MACHINE PERSONCODE COST
1 MachineA8 50
1 MachineA7
1 MachineB6
2 MachineA3 70
2 MachineA2
2 MachineA1
3 MachineA4 100

[code]....