60% of what number is 72?

Afarmer has a large field that is x feet in length. he wants to fence in a rectangular section in the middle of the field , leaving a length of 100 feet of open field behind each end of the fenced rectangle.he also wants the width of the fenced-in space to be 100 feet less than its length. find the expressions to represent the length and width of the fenced section of the field

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

David leaves his house to go to school. he walks 200 meters west and 300 meters north. how far is david from his original starting point?