Answer: A. 51%
Step-by-step explanation:
Area of circle =
, where r = radius of the circle.
In the figure below, we have the complete question.
According to that,
Radius of outer circle = 7ft
Radius of inner circle = 5ft
The probability that the thumbtack will be placed on the inner circle
[π is canceled from numerator and denominator
in percent, 
So, the probability that the thumbtack will be placed on the inner circle = 51%
Hence, the correct option is A. 51%.
Answer:
Steps
8x9 (or 8*9 or also seen as (8)(9) ) = 72
The answer for question 4:
a) 3(3n-1)=9n-3
b) 9n-3=96
9n=96+3
9n=99
n=11
A^2+b^2=c^2 that is a formula