ISI2018-DCG-21

Question

A box with a square base of length $x$ and height $y$ has an open top and its volume is $32$ cubic centimetres, as shown in the figure below. The values of $x$ and $y$ that minimize the surface area of the box are

• A. $x=4$ cm $\&$ $y=2 $ cm
• B. $x=3$ cm $\&$ $y=\frac{32}{9} $ cm
• C. $x=2$ cm $\&$ $y=8 $ cm
• D. none of these.