You instructor is considering the installation of a circular dart board with radius 5.1 on the office wall. instead of actually reading your papers, it has been suggested that grades be assigned by chance by dividing the board into three grade sectors and tossing a dart.

the area of an "a" sector with central angle 2.781⁰
the area of a "b" sector with central angle 1.54519⁰
the area of a "c" sector with central angle 112.128⁰

Naruto is choosing between two venues that will deliver food to his house. with probability 1/3 he will choose ramen mania (r), and with probability 2/3 he will choose sushi (s). if he chooses r, 15 minutes after making the call, the remaining time it takes the food to arrive is exponentially distributed with average 10 minutes. if he orders s, 10 minutes after making the call, the time it takes the food to arrive is exponentially distributed with an average of 12 minutes. given that he has already waited 25 minutes after calling, and the food has not arrived, what is the probability that he ordered from r? i am really stuck on how to set this up, so if you could be extra clear, that would be super ! in advance