9.8 meters divided by .14 meter pieces. 70 pieces that Ralph can cut from the spool.
As the word suggests, a quarter-sphere is a quarter of a sphere, and thus the volume of a quarter-sphere is a quarter of the volume of the sphere.
The volume of a sphere is computed as

So, the volume of a quarter-sphere is

Answer to 4.
About 106.66
If they ask if a rounded answer it would be 107. You just divide 2560 by 24 because you know 24 balls is 3 pounds.
An equation
what else could it be?