Membrane Potential and Permittivity

[alex_b93]

Hi,
Was wondering if I could get some help with part b of this question?
I've attached the question and my attempt in the pictures as there was a lot of data and writing, so thought this would be the easiest way.

With my attempt I think I'm missing something pretty obvious, but I'm drawing a blank on it.

Cheers

Homework Statement

See pictures attached

Homework Equations

See pictures attached

The Attempt at a Solution

See pictures attached

 

[alex_b93]

Can anyone help at all?