Friendly$$s Quick Loans, Incorporated, offers you $$four for five or I knock on your door.$$ This means you get $$4$ today and repay $$5$ when you get your paycheck in one week $($or else$).$

a$.$ If you were brave enough to ask, what APR would Friendly$$s say you were paying? $($Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$ b$.$ What$$s the EAR Friendly$$s earns on this lending business? $($Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$