What is the electron concentration in a p-doped semiconductor?

[peanutbutter]

A semiconductor material has an intrinsic carrier concentration of 5.6 x 10^14 m^-3 at 300K.
What is the electron concentration when such a semiconductor is p doped with an acceptor concentration Na = 3.9 x 10^18 m-3.

I have no idea how to approach this question without a value for the energy band gap. Could someone point me in the right direction? Thanks.

 

[Defennder]

Why do you need the value of Eg for this question? You only need a simple equation for this question.

 

[peanutbutter]

Why do you need the value of Eg for this question? You only need a simple equation for this question.

Thanks for the boost in confidence, I've worked it out now anyway.