Please help me solve these questions step by step:

Barry has just taken out a $200,000, 30-year, 5% mortgage. He has heard from friends that if he increases the size of his monthly payment by one-twelfth of the monthly payment, then he will be able to: (1) pay off the loan much earlier, and (2) save a bundle on interest costs. Barry is not convinced. Use the necessary calculations to help convince him that his friends are speaking the truth.