SOLUTION: An apple with a diameter of 6.3” (assume the shape of a sphere) has a “bruise” with an area of 1 square inch. What is the probability of biting into the bruise? (Area of a sphere =

Algebra ->  Probability-and-statistics -> SOLUTION: An apple with a diameter of 6.3” (assume the shape of a sphere) has a “bruise” with an area of 1 square inch. What is the probability of biting into the bruise? (Area of a sphere =      Log On


   

Question 472906: An apple with a diameter of 6.3” (assume the shape of a sphere) has a “bruise” with an area of 1 square inch. What is the probability of biting into the bruise? (Area of a sphere = 4)
when i do this i don't get any of these choices.
choices:
2.5% 0.75% 1.5% 0.20%
Found 2 solutions by Alan3354, Theo:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
The area of a sphere is not 4.
Area+=+4%2Api%2Ar%5E2+=+4%2A3.15%5E2%2Api
Area =~ 124.69 sq in
-------------
1/Area =~ 0.00802
--> 0.802%

Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
i don't come up with any of those answers either.
i have no idea what they had in mind when they presented this problem.
if you go by a simple area of the apple that is exposed versus area of the apple that is bruised, then the answer would be:
1/124.6898124.
that would be 1 square inch of the bruise divided by the total area of the apple.
that total area is calculated by the formula 4*pi*r^2.
since the diameter of the apple is 6.3, then the radius is 3.15, and the formula becomes 4*pi*3.15^2 which equals 124.6898124 square inches.
1/124.6898124 = .008019901 which is equal to .8019901% which rounds to .80%.
quite frankly, i don't understand how you are supposed to come up with an answer to this question.
sorry i couldn't help you on this.
perhaps you might feel better because somebody else doesn't understand it either?