
Step-by-step explanation
Step 1
Pyramid:
the volume of a pyramid with square base is given by:

then, let
heigth=12 ft
length=10 ft
now, replace.

Step 2
Cone:
the volume of a cone is given by:

then, Let
heigth= 8 in
radius= 6 in
now, replace.

I hope this helps you