The manager of a department store wants to build a 600
square foot rectangular enclosure on the store's parking lot in
order to display some equipment. Three of the sides of the
enclosure will be built of redwood fencing, at a cost of $7 per
linear foot. The fourth side will be built of cement blocks, at a
cost of $14 per linear foot. Find the dimensions of the
enclosure that will minimize the total cost of the building
materials.
A farmer has $1500 available to build an E-shaped fance
along a straight river so as to create two identical rectangular
pastures. The materials for the side parallel to the river cost
$6 per foot and the materials for the three sections
perpendicular to the river cost $5 per foot. Find the
dimensions for which the total area is as large as possible.
#4) A rectangular storage container with an open top is to
have a volume of 10 m3. The length of its base is twice the
width. Material for the sides costs $6 per m2. . Material for
the base costs $10 per m2. Find the cost of materials for the
cheapest such container.