Answer:
V(b) = 576 in³
Explanation:
9 = 3 * 3
12 = 3 * 2 *2
To have 9 spheres in a box 12 x 12 in²
We need to arrange in a grid of 3 x 3 spheres of 4" diameter, then
three rows and three columns will fit exactly i the box 12 x 12 in²
Now the height of the box need to be adequate for the diameter of the spheres ( 4 in )
Therefore the total volume of the box is:
V(b) = 12*12*4
V(b) = 576 in³