Angela loans Kathy $$8,000.$ Kathy repays the loan by paying $$6,000$ at the

end of one and a half years and $$4,000$ at the end of three years. The money

received at t D $11$ is immediately reinvested at an annual effective interest $2$

rate of $6\%.$ Find Kathy$$s annual effective rate of interest and Angela$$s annual

yield.