Answer:
72 units³
Step-by-step explanation:
length = 12 units
height = 4 units
width = 3 units (8 - 5 = 3)
12 x 3 x 4 = 144
144 / 2 = 72
The answer is
f(n)=6(3^n-1)
Which is the third option
Explanation :
Plug in the n values in the equation
Example : 6(3^1-1)
3^0=1
6(1)=6
I hope I helped
This problem is basically asking:

Which would mean 