Question

The volume of a right circular cone is 5 lires.Calculate the volume of the two parts into which the cone is divided by a plane parallel to the base, one-third of the way down from the vertex to the base.Give your answer to the nearest metre

Answer 1

b is base diameter

h is total height
so top one is b/3 and h/3
area of base =(1/4) pi b^2
vol of big = (1/3) h * (1/4) pi b^2 = (1/12) pi h b^2 = 5
volume of similar objects in ratio of length^3
(1/3)^3 = 1/27
so
vol of small = (1/27) vol of big
vol of bottom = vol of big - vol of small