Ans: We may recall that the expression for electric flux through a surface enclosing charge q by Gauss’s law is given by,
Where, is the permittivity of the medium.
Now the electric flux through sphere is given by,
Since there is no additional charge between the given two spheres, the flux through sphere is given by,
We could now get the ratio of flux through spheres 5, and ,
Therefore, we find the required ratio to be .