Answer:
440 square inches.
Step-by-step explanation:
We can consider the boxes as one single shape.
So it's base area is 12×10=120 and the area of the side faces is 20×12=240 and 20×10=200.
Now, there are 2 of each, so let's add up everything and multiply by 2.
(120+240+200)×3=560 square inches.
But we have to take off the base, so:
560-120=440 square inches