please solve this.....

Let r and h be respectively the radii and heights of the smaller cone.

Let R be the radius of the bigger cone. Its height is given to be 36

Using  similarity of triangles,

 we get,

 r/R=h/36

It's given that the volumes are in the ratio 8:27.

So,

So we conclude that the section is made 12 cm (36-24=12) above the base.