The volume
of a cone with base radius
and height
is

Similarly, the volume
of a sphere with radius
is

We know that
and that 
So, we can set up the following equation:

We can simplify the common denominator 3, and pi appearing on both sides:

We can divide both sides by 4:

Without further information, this is all we can say: the cubed radius of the sphere is the same as 24 times the squared radius of the cone.
Answer:
6
Step-by-step explanation:
Deisha's build rate = 1 fence per 15 hours = 1/15 fences per hour
Travis's build rate = 1 fence per 12 hours = 1/12 fences per hour
Working together, their combined rate is 1/15 + 1/12 = 3/20 fences per hour
So it takes them 20/3 = 6 2/3 hours per fence