What is the present value of $$25,000$ received today, $$1,500$ received at the end of each of the next six years and $$8,000$ received at the end of the $7$th year, assuming a required rate of return of $6\mathrm{.}50\%?$a$.$ $$38,143$b$.$ $$16,899\mathrm{.}89$c$.$ $$29,990\mathrm{.}22$d$.$ $$37,410$