a charge q is at one corner of cube. what is flux through all six faces of cube

Assume that the charge is located at origin and the corner of the cube also at origin.
Using Gauss's law and symmetrical argument:
 now if we place 7 more cubes around original cube. Each face of this new cube contains 4 faces of original.
The new big cube has 6 faces placed symmetrically around origin, total= 24 faces.
now the total flux according to Gauss's law is q/epsilon0.
therefore,  flux through each face is q/24 epsilon0.

 

Thanks.