A hunter is at a point along a river bank. He wants to get to his cabin, located 5 miles north and 7 miles west. (See figure.) He can travel 5 mph along the river but only 2 mph on the rocky land. How far upriver should he go in order to reach the cabin in minimum time?

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?