In a double-layer insulation configuration, if the first layer is 6" x 2", what top layer size is used to reach 6" x 4"?

• A. 8" x 2"
• B. 10" x 2"
• C. 12" x 2"
• D. 4" x 2"

Answer: (B)

This item tests how you combine two insulation pieces to reach a specific finished size by overlapping. You start with the bottom layer that’s 6" long and 2" wide. To end up with a final size of 6" by 4", you need an extra 2" of width, which comes from the top layer, and the top layer must be long enough to overlap the bottom so you can align to the desired length. A top piece that is 10" long and 2" wide gives you enough material to place over the bottom with an overlap that yields the needed width and length after fitting. Shorter options wouldn’t provide the necessary overlap on both ends, while longer options would be wasteful. So the top layer should be 10" x 2".