Answer:
422 cm²
Explanation:
Small rectangular prism: 3*4 + 8*3 + 8*3 + 8*4 + 8*4 = 124
Large rectangular prism: 5*7 + 5*7 + 10*5 + 10*5 + 10*7 + (10*7 - 4*3 ) = 298
Total: 124 + 298 = 422 cm²
*Calculate only areas of surfaces showing and add them up
The small rectangular prism has 5, and the large rectangular prism has 6 (with a 4*3 rectangle on its top surface covered)