Area of Bull's Eye:
A = π r²
  = π (1)²
  = π
Area of Inner Ring:
A = π r²
  = π (3-1)²
  = 4π
Ratio between Inner Ring and Bull's Eye:
[tex]\frac{InnerRing}{Bull's Eye} = \frac{4\pi }{\pi} = 4[/tex]
Answer: It is 4 times harder to hit the Bull's Eye than it is to hit the Inner Ring