ok so first what you do is you find out which sides have the smallest and largest surface areas
largest: 50x5 (250in)
smallest: 5x3 (15in)
what you would do if you wanted the smallest surface is you would glue the 50x5 surfaces together like this: |_| if the 5in sides are facing to the side
smallest like this: ||| if the 5in sides are facing to the side