Assume a cell with the following properties: [Na]out = 120 mM; [Na]in = 12 mM [K]out = 5 mM; [K]in = 125 mM Membrane is permeable only to Na+ and K+ If the plasma membrane of the cell becomes more permeable to Na+, both influx of Na+ into the cell and the Na+ equilibrium potential will increase.

This statement is not correct because the Na+ equilibrium potential remains the same, it is only depends on concentration gradient.

Explanation:

Na+ influx will increase, but Na+ equilibrium potential will not change because the concentration of K+ ions are high inside the membrane and that of Na+ ions are high too outside the membrane. Membrane potential will be generated that helps in the diffusion of the ions through the pore in both in and outside of the cell. When the concentration of Na+ ions increase, Na+ ions diffuse from outside to the inside of the cell therefore increase the influx  

sorry, but you do not have posted the diagram.