How much LESS did Walter pay than he would have paid if Byron had transported the materials?

Walter hired Byron to refloor a 12-foot by 12-foot rectangular room. To save some money, Walter transported the materials himself.

How much LESS did Walter pay than he would have paid if Byron had transported the materials?
A . $ 250
B . $ 600
C . $1200
D . $3600
E . Not enough information is given.

Answer: A