I am having issues with this homework finance assignment, could someone please help?

(Related to Checkpoint 5.4) (Present value) Sarah Wiggum would like to make a single investment and have $22 million at the time of her retirement in 32 years. She has found a mutual fund that will eam 8 percent annually How much will Sarah have to invest today? If Sarah earned an annual return of 18 percent, how soon could she then retire?