Determine the IRR on the following projects:

a. An initial outlay of $9,000 resulting in a single free cash flow of $16,758 after 7 years

b. An initial outlay of $9,000 resulting in a single free cash flow of $48,555 after 14 years

c. An initial outlay of $9,000 resulting in a single free cash flow of $107,703 after 23 years

d. An initial outlay of $9,000 resulting in a single free cash flow of $13,812 after 2 years