A loan is negotiated with the lender agreeing to accept $15,000 after 10 years, $25,000 after 20 years, and $40,000 after 30 years in full repayment. The borrower wishes to liquidate the loan with a single $80,000 payment. Let T represent the time of the $80,000 payment calculated by an equation of value. If i = 0.01, nd T by using exact calculation and by linear interpolation (using two integral values of T with dierence one).