5-10A. (Solving for i in Annuities) Ellen Denis, a sophomore mechanical engineering student, receives a call from an insurance agent, who believes that Ellen is an older woman ready to Page 6 of 10 retire from teaching. He talks to her about several annuities that she could buy that would guarantee her an annual fixed income. The annuities are as follows: Initial Payment into Annuity Amount of Money Duration of Annuity Annuity (at t=0) Received per year (Years) A $50,000 $8500 12 B $60,000 $7000 25 $70.000 $8000 20