dudewtf

Please, I really need help with this!

I'm reviewing for an exam and ran across a question that has me rather stumped. I tried simply applying the Nernst equation but it seems I'm still missing something importantn

"An electrically excitable cell with a resting potential of -70mV the following conditions are present (temperature is 37°C):

Intracellulär Extracellular
K+ 160nM 5mM
Na+ 20nM 140mM
Cl- 10nM 120mM
Ca2+ 100mM 1mM

1. When the cell depolarisering [Ca2+] rises to 15uM, while the membrane potential reaches +61mV. Under these conditions , would Ca2+ move Into or out of the cell?

2. Which way would Na+ move?

3. Which way would K+ move if Na+ were allowed to dominate?

The above is my translation! Let me know if something is unclear.

Now, my problem is mainly question number 3, I honestly have no idea how to approac this. I've tried asking friends as well and the don't really understand how to answer that either.

EDIT: Edited for clarity