Answer:
470
Step-by-step explanation:
there are several surface areas.
1. the 4 side walls of the big block = 4*12*7 = 336
2. top and bottom of the big block = 2* 7*7 = 98
3. subtract the small rectangular area from the top area covered by the small block = 2*7 = 14
4. the 3 (visible) side walls of the small block on top =
3* 2*7 = 42
5. the small top and bottom areas of the small block =
2* 2*2 = 8
so, 1.+2.-3.+4.+5. = 470
