James has 2 outside dogs that need a fenced in yard. They both like their own space to relax, but also like to play together sometimes.

1.    James has 2 outside dogs that need a fenced in yard.  They both like their own space to relax, but also like to play together sometimes.  James decides to fence the yard like the picture below in order to accommodate the dogs. Note that the size of each individual space is the same and the shared space is double the size of the individual spaces.  

     Answer all parts in complete sentences including units.

a)     If he has 80 linear yards of fencing, what is the maximum total area that he can fence?

b)    Suppose James decides that he needs each individual space to be 60 square yards and that the exterior fencing needs to be stronger than that of the interior. The fencing he wants to use will cost $8 per linear yard on the exterior fence and $6 per linear yard for the fencing on the interior of the space.  What is the minimum cost of the fenced in space?