Your lovely wife has decided to buy you a vacuum cleaner for your birthday (she always supports you in your hobbies . . .). She called your best friend, a manager of a vacuum cleaner store, and he has suggested one of two payment plans: She can either pay $100 now or make 12 monthly payments of $10 each, starting from today. What are the monthly IRR and the EAIR of the payment-over-time plan?