Today is your birthday, your friend agrees to pay you $100 every month for 1 year, with the first payment being paid today. Your friend is very trustworthy and will make every payment on time, and the market rate for your friend is 12%. What is the present value (monetary value only) of this birthday gift?

correct answer is: 1,136.73 1%

but show me how to solve this and which factors to use! show all work!