May be this is easier than you think

Electricity and Magnetism Level 3

A cube of side $a$ and uniform charge density $\rho$ has electric field $E$ at one of its corners.

A cube of side $\dfrac a2$ is removed from that corner. The electric field at this point is now $E_2$ . Find $\dfrac{E_2}E$ .

\frac18

\frac14

\frac38

\frac12

\frac58

\frac78

1

None of these choices