Question

Suppose you have two rectangular prism with dimensions 2 feet by 3 feet by 5 feet. You want to join prisms together to form a larger rectangular prism. Which faces should you join if you want to make a prism with the least possible surface area?

Answer 1

Below in bold.

Explanation:

You would join the faces with the greatest area

That is the faces with dimensions 3 feet by 5 feet.