Determine the IRR on the following projects:
a. An initial outlay of $9,000 resulting in a single free cash flow of $17,118 after 7 years

____%
b. An initial outlay of $9,000 resulting in a single free cash flow of $46,991 after 13 years

____%
c. An initial outlay of $9,000 resulting in a single free cash flow of $109,128 after 19 years

____%
d. An initial outlay of $9,000 resulting in a single free cash flow of $13,542 after 4 years

____%