How many halves are in three wholes

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.

Which expression is equivalent to the expression shown?

How much dextrose 70% must be mixed with dextrose 5% to prepare 1,000 ml of dextrose 20%?