I got the same as you but I think you forgot to mention that the pill box has a square section
A jeweler wishes to make a rectangular pill box such that the top and bottom will be copper plated and the sides silver plated. If silver plating costs $6 per cm^2 and copper plating costs $2 per cm^2, wat are the dimensions o he least costly pill box having 8/3 cm^2 as its volume?
I got 2/3 cm by 2 cm by 2 cm