quasi Fermi levels,conductivity

An undoped Si sample is optically excited at 300K such that Gop=10^19 ehp/cm^3s and taun=taup=1 microseconds.

(a) What is the separation of the quasi Fermi levels (Efn-Efp)?
(b) Where is Efn and Efp with respect to the intrinsic Fermi level Ei?
(c) What is the change in conductivity due to excess carriers?

What are the answers and how did you find them?

Thank you.

---I double checked.  There is no further information or parameters given with this problem.  I'm stumped.