Both 1 and 2 are grammatically correct, but have slightly different meanings. 1 is how a native speaker would speak. 2 is written in the passive voice (you don't say 'who' is asking the worker, you say 'couldn't someone be asked...?' (without saying 'we' should ask) and so has a less understandable meaning in this context.
3 doesn't quite make sense, as you can't ask someone 'for' the work, they must 'do' the work. If you ask 'for' the work, it means you ask them to show you it/ give you it, and so doesn't make sense as you go on to say 'done....' (to do).
Hope this helps!