Answer:
The hollow ball is more buoyant than the solid ball.
Step-by-step explanation:
The hollow ball will float while the solid ball sinks because the volume of water displaced by the hollow ball is more than that displaced by the solid ball.
An object floats when it displaces a volume of water equal to its weight. A solid ball is more compact, and hence, does not displace a lot of water when dropped into a bowl full of water. On the other hand, the hollow ball will have a larger curved surface area, since it has no fill. This will make it displace a larger volume of water and hence make it float.