What is the electric flux φ through each of the six faces of the cube?

For the complete answer to the question above,  phi = q/(6*epsilon(0)) 

Gauss' law tells us that the total flux through a closed surface, in this case, a cube, is equal to the charge enclosed, q, divided by epsilon(0). 

phi = q/epsilon(0) 

Since the point charge is in the center of the cube, each face will have an equal amount of flux going through it, i.e. one-sixth. 

This gives us 

phi = q/(6*epsilon(0)) 

The magnets are probably damaged or there not strong enough to attached to the refrigerator