Ubuntu Error

Question

Whenever I to run Synaptic Manager and I get this error message -error:E: Type "wget" is not known on line 74 in source list /etc/apt/sources.listE: The list of sources could not be readGo to the repository dialog to correct the problem.E:_cache->open()failed, please report.That's one error.What's the source of this problem? Will i need to reinstall my OS?