Posted by Murali on .
Bill Ding plans to build a new hardware store. He buys a rectangular lot that is 50 ft by 200 ft, the 50foot dimension being along the street. The store is to have an area of 4000 square feet. Construction costs $100 per linear foot for the part of the store along the street and only $80 per linear foot for the parts along the sides and back. To what dimensions should Bill build the store in order to minimize the construction coast?

Maths 
Henry,
Use the entire 200 ft dimension to
minimize cost:
200W = 4000 SQ FT,
W = 4000 / 200 = 20 FT.
L * W = 200 * 20.