Can you explain me this question? No excel or chegg answer please

Your firm is considering purchasing an old office building with an estimated remaining service life of 20 years. Recently, the tenants signed a long-term lease, which leads you to believe that the rental income would be $150,000 for the first year and increases at a rate of 3% per year for the first ten years, and $220,000 for the 11th year increasing by 4% per year for the following years. You estimate that operating expenses, including income taxes, will be $50,000 for the first year and increases by $5,000 each year thereafter. You also estimate that razing the building and selling the lot on which it stands will realize a net amount of $100,000 at the end of the 20 -year period. If you had the opportunity to invest your money else-where and thereby earn interest at the rate of 12% per year, what would be the maximum amount you would be willing to pay for the building and lot at the present time? Your firm is considering purchasing an old office building with an estimated remaining service life of 20 years. Recently, the tenants signed a long-term lease, which leads you to believe that the rental income would be $150,000 for the first year and increases at a rate of 3% per year for the first ten years, and $220,000 for the 11th year increasing by 4% per year for the following years. You estimate that operating expenses, including income taxes, will be $50,000 for the first year and increases by $5,000 each year thereafter. You also estimate that razing the building and selling the lot on which it stands will realize a net amount of $100,000 at the end of the 20 -year period. If you had the opportunity to invest your money else-where and thereby earn interest at the rate of 12% per year, what would be the maximum amount you would be willing to pay for the building and lot at the present time