Abox of books has than a box of cotton balls.

Talking about a quantity of inertia is exactly the same as talking about a quantity of mass.  So, if the boxes are anywhere near the same size, then the box of books has more inertia than the box of cotton balls, because books have more mass than an identical volume of cotton.

A box of books has more inertia than a box of cotton balls.

Explanation:

Inertia is related to the mass of the object. Inertia is usually defined as the resistance offered by the object in response to the movement or the velocity of the object.

The object will higher mass will have higher inertia as it should offer more resistance to remain in inertia and the object with lesser mas can offer smaller resistance comparatively. So here, the box of books has more inertia than a box of cotton balls.

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.