DellDell Dell A215 Black Multimedia 2 Channel Computer Speakers

will these speakers work with mp3 players?

I rec'd my new Dell Desktop on 12/1/14 and the above A215 speakers were in the box but show a ship date from 2005, but say new. Are they 10 yrs old??

I have these speakers, but I haven't used them for some time. I lost the power cord. Do I need to call Dell to get another, or is there a generic?

Will these work with any brand desk top computer?