Answer:
They will move out of the potato into the salt solution. 75 water molecules.
Explanation:
Molecules like to be at an equilibrium, so if it is more salty on one side, the water molecules on the other side are going to move to the salty side in an attempt to lower the salt concentration. In order to reach the equilibrium they want, both sides have to have equal numbers of water molecules so in this case, about 75 water molecules will leave the potato and move into the solution so that both the potato and the solution have 125 total water molecules.
