10. 11.10 Your parents are in the process of having a new house designed. A total of 150 cubic yards of foundation concrete must be poured for the current 1-story design. The equipment required to pour the concrete by experienced workers is 2 gasoline engine vibrators and 1 concrete pump. The vibrators cost $76 per day and the pump costs $580 per day. The contractor states that only 1 day of equipment rental is needed to pour the foundation.

(a) Your dad asked you to estimate the cost of the equipment per cubic yard of concrete.

(b) A 2-story house will have a smaller footprint and require only 90 cubic yards of concrete. Now estimate the equipment cost for him, assuming partial-day charges for the equipment are not possible. What is the percent change in cost per cubic yard going from a 1-story to 2-story design?