Final answer:
Increasing the mass on one side of a system shifts the center of mass towards that heavier side; hence, changing the mass to 5 kg on the right would move the center of mass to the right.
Step-by-step explanation:
If the mass on the right was changed to 5 kg, the position of the center of mass would move to the right. This is because the center of mass is the point that represents the average location of all the mass in a system. When one side becomes heavier, the center of mass shifts towards that side.
The center of mass is calculated by taking the weighted average of the positions of all masses in the system, so increasing the mass on one side without changing the position of the masses means the center of mass will shift towards the heavier side. In this case, since the mass on the right is increased, the center of mass will shift towards the right.