A concrete plant is considering a new piece of equipment with an initial cost of $$75,000$ and market value of $$15,000$ at the end of its $25-$year useful life. The annual maintenance cost for this piece of equipment is projected to be $$10,500.$ The equipment will produce an annual labor savings of $$24,000.$ What is the approximate projected before$-$tax rate of return on the equipment?

a$.22\mathrm{.}4\%$

b$.17\mathrm{.}8\%$

c$.5\mathrm{.}7\%$

d$.19\mathrm{.}3\%$