SOLUTION: the diameter of a regulation size dartboard is 18in. What is the probablity of hitting the triple 20?

Algebra ->  Surface-area -> SOLUTION: the diameter of a regulation size dartboard is 18in. What is the probablity of hitting the triple 20?      Log On


   

Question 363562: the diameter of a regulation size dartboard is 18in. What is the probablity of hitting the triple 20?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
You need to find the area of the triple 20 region A%5Bt20%5D.
Then the probability of hitting a triple 20 is the total area of a triple 20 region divided by the area of the entire dartboard A%5Bt%5D.
A%5Bt%5D=pi%2A%28D%5E2%2F4%29=pi%2A%2818%29%5E2%2F4=%2881%2F4%29pi
P=A%5Bt20%5D%2F%28%2881%2F4%29pi%29
highlight%28P=%284%2AA%5Bt20%5D%29%2F%2881%2Api%29%29