A tanker truck has overturned and is spilling oil onto the highway. Amazingly, the region covered by the oil spill maintains a perfectly circular shape. The area covered by the spill is growing at a rate of 40π square feet per minute. How quickly is the radius of the oil spill growing when it covers an area of 100π square feet?

Me its important ! marge runs an ice cream parlor. her speciality is triple chocolate sundaes. she can prepare 1 sundae every 2 minutes, and she earns $1.20 for each sundae she makes . if she just makes sundaes for a single shift of at most 4 hours and at least 2 hours , which function relates her earnings to the number of minutes she works?