The surface area of the composite figure, formed by attaching a 10x0.5x7-inch prism to a 10x1x4-inch prism, is 275 square inches. Calculated by summing the individual prism surface areas.
To find the surface area of the composite figure, calculate the surface area of each prism separately and then add them together.
1. Surface area of the first prism (10 inches by 0.5 feet by 7 inches):
![\[2(10 * 0.5) + 2(10 * 7) + 2(0.5 * 7) = 20 + 140 + 7 = 167 \text{ square inches}\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/rz92usm2zwhove3a9dagwsuwuq3oz7ko7t.png)
2. Surface area of the second prism (10 inches by 1 foot by 4 inches):
![\[2(10 * 1) + 2(10 * 4) + 2(1 * 4) = 20 + 80 + 8 = 108 \text{ square inches}\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/gvbzm05inx5awezt7i7jyaghw0n4ew0baf.png)
3. Total surface area of the composite figure:
![\[167 + 108 = 275 \text{ square inches}\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/77pkrt720h7b6pnsz7eomlae3sszequhb8.png)
Therefore, the surface area of the composite figure is 275 square inches.