A backhoe with a $2-$cy bucket will be used for excavating the basement of a building. The dimensions

of the basement are $200-ft$ wide, $400-ft$ long, and $8-ft$ deep. The earth is hard, tough clay. The

backhoe will load earth into $18-$cy$,$ loose measure, trucks that will haul the earth $10$ miles to a waste

dump. The average haul speed will be $40mi\frac{.}{h}r$ and return speed of $45mi\frac{.}{h}r.$ For each truck assume

a fixed time of $5$ min $.$ to dump a load and wait at the basement area to be loaded.

The cost of the backhoe, with operator, is $$\frac{105\mathrm{.}00}{h}r$ and the cost of each truck, with driver, is

$$\frac{65\mathrm{.}00}{h}r.$ Assume a $45-$min. effective hour for the loading and hauling operation. Estimate the total

cost and cost per cubic yard, bank measure, based on using the adequate number of trucks to balance

the production rate of trucks and the backhoe.