Can someone please try solving this problem? Step by step explanation please

The radius of a sphere is 3 inches. which represents the volume of the sphere?

Randy and trey take turns cleaning offices on the weekends. it takes randy at most 4 hours to clean the offices. it takes trey at most 6 hours to clean the offices. what is the greatest amount of time it would take them to clean the offices together? 2.4 hours 2.5 hours

The water aquarium shark tank is always greater than 25 feet of the water level decreased by 6 feet during cleaning what was the water level before the cleaners took out any water