A Bank makes a loan to Sean at 12.5 percent per year to be repaid by level annual payments for t years. Exactly one year before the loan is to be terminated, Sean notices that the decrease in outstanding loan balance since he took out the loan is 18,027.36. Seans last payment contains 461.58 in interest paid.

Exactly what was the term of Seans loan?

I need steps or formulas for the answer, do not just use excel or financial calculator