I really need help with this and plz give me the reasoning. Thx

What is the volume of the sphere shown below with a radius of 3?

Yvaries inversely as x. y =12 when x=5. find y when x=4

Aprobability experiment is conducted in which the sample space of the experiment is s={7,8,9,10,11,12,13,14,15,16,17,18}, event f={7,8,9,10,11,12}, and event g={11,12,13,14}. assume that each outcome is equally likely. list the outcomes in f or g. find p(f or g) by counting the number of outcomes in f or g. determine p(f or g) using the general addition rule.