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
Answers: A) 2:7 B) 1:7 C) 3:5 D) 3:7 E) 3:4
area of first circle = pi*(x)^2 = pi*x^2   area of second circle = pi*(2x)^2 = 4*pi*x^2   area of third circle = pi*(3x)^2 = 9*pi*x^2   area of fourth circle = pi*(4x)^2 = 16*pi*x^2   area b/w 1st and 2nd circles = 3*pi*x^2   area b/w 3rd and 4th circles = 7*pi*x^2   so ratio = 3:7   ANSWER:3:7
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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