Who would make the most money a head mechanic, a assistant mechanic, a sales manager ,or a desk clerk

Acollege is planning to construct a rectangular parking lot on land bordered on one side by a highway. the plan is to use 680 feet of fencing to fence off the other three sides. what dimensions should the lot have if the enclosed area is to be a maximum?

Can someone me out here number 4 plz

At 6 1/2 cents per pound of string beans how much does 7 pounds cost