A closed box to be found to have length 2ft, witdh 4ft and hight 3ft, where the measurement of each dimension is made with a maximum possible error of +-0.02ft. The top of the box is made from material that costs only 2 Dollars/$\displaystyle ft^2$. The material for the sides and bottom costs only 1.50 Dollars/$\displaystyle ft^2$. What is the maximum error involved in the computation of the cost of the box?

1) In that question, gonna find top,bottom and side surface areas with errors and calculate the cost?

2) Couldn't understand what it wants in question as answer. The difference between max and min value? ,, Only max value? or Only min value? ...

3) Just noticed that i dont know how to make multiplying with errors. So how can i calculate areas with errors?

p.s.--> I asked that question before but i just noticed that i didn't write the information about cost of sides and bottom. Now the question is complete.