Final answer:
In an NaK pump, for every molecule of ATP hydrolyzed inside the cell, three sodium ions and two potassium ions are pumped in and out of the cell.
Step-by-step explanation:
The sodium-potassium pump, also known as Na/K+ ATPase, moves sodium ions out of the cell and potassium ions into the cell.
For every molecule of ATP hydrolyzed inside the cell, the sodium-potassium pump pumps out three sodium ions (Na+) and pumps in two potassium ions (K+).