I'm not aware of any problem that can't be solved with either C, LISP or both.
This might be a good time to bring up the phrase "Turing Tar-Pit". To summarize, while any Turing-complete language can solve all computable problems, there are still significant differences in their expressive powers.
The fact that you
can solve any problem in C or LISP does not imply that you
should attempt to solve all problems in C or LISP.