(IRR calculation) Determine the IRR on the following projects: a. An initial outlay of $12,000 resulting in a single free cash flow of $16,581 after 8 years b. An initial outlay of $12,000 resulting in a single free cash flow of $49,631 after 15 years c. An initial outlay of $12,000 resulting in a single free cash flow of $110,694 after 19 years d. An initial outlay of $12,000 resulting in a single free cash flow of $13,862 after 4 years