At first, I thought this was going to be a dog of a bear of a problem,
but then I fixated it with my steely burning gaze and it fell apart for me.
The volume of a pyramid is (1/3) (base area) (height)
Each of these pyramids has the same base area and the
same height, so ...
Volume of the lower pyramid = (1/3) (base area) (height)
Volume of the upper pyramid = (1/3) (base area) (height)
Combined volume of both pyramids = (2/3) (base area) (height) .
Now, how do the pyramids relate to the rectangular prism ?
Their base area is (length x width) of the prism, and
their height is (1/2 the height) of the prism.
From here, we'll work with the dimensions of the prism ... L, W, and H .
Combined volume of the pyramids = (2/3) (L x W) (1/2 H)
= (1/3) (L x W x H) .
Volume of the prism = (L x W x H)
The pyramids occupy 1/3 the volume of the prism.
The ratio is 1/3 .
