1. The problem statement, all variables and given/known data The problem ask to calculate the interest rate of a loan. The principal is $735 000, term is 25 years (300 months), and the repayments due is $4656.17/month. i = interest rate, PV = present value, R = repayments 2. Relevant equations PV = R x [(1+i/12)^300 - 1]/(i/12) 3. The attempt at a solution I managed to calculate the total interest to pay = $661 851 735000 = 4656.17 x [(1+i/12)^300 - 1]/(i/12) 13.155 = [(1+i/12)^300 - 1]/i 13.155i = [(1+i/12)^300 - 1] 13.155i + 1 = (1+i/12)^300 I realised that this may not be correct but I have no idea of what to do. I put this into an online calculator and it gave a value of 5.823% but I don't know how it got to it. Please help.