four concentric circles r given .the radius of 1st circle is x.next is 2x,then 3x and 4x. given that area b/w 2nd and 1st is A and 4th and 3rd circles being B.find ratio of A to B

• 3:7
  
  Area A=2*pie*3X^2
  Area B=2*pie*7x^2
  A:B=3:7
• 12 years agoHelpfull: Yes(6) No(2)
• ANS : 3/7
  Area of nth circle = pi*(nx)^2
  area b/w 1st and 2nd circles = pi*((2x)^2-(x)^2)
  A = 3*pi*x^2
  area b/w 3rd and 4th circles = pi*((4x)^2-(3x)^2)
  B = 7*pi*x^2
  A/B = 3/7
  
  
• 11 years agoHelpfull: Yes(6) No(0)