I need help, please explain the answer

Acircular city park has a sidewalk directly through the middle that is 111 - feet long. if each bag of fertilizer covers 50 square feet, then determine how many bags of fertilizers the parks and recreation department needs to use to cover the circular park. ignore all the sidewalks around and through the park.

Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?

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