Two circular frames are kept one above the other. Frame X has a diameter of 16 cm and Frame Y has a diameter of 12 cm. What fraction of the surface of Frame X is not covered by Frame Y?	Pick one:
A) 3/5  B) 7/16  C) 12/16  D) 24/12  E) 2/3
The questions asks us to find the surface which is not covered by the Frame Y i.e., area of the surface not covered.   Where as circumference is the length along the edge of the circle,   2*pi*r implies the length of the curve   pi*r^2 implies area enclosed by that curve..hence Area of the circle is considered for this problem   Area of the Frame Y=pi* r^2, where r=6   =&gt;pi*36   Area of the Frame X=pi*64   Surface not covered by the Frame Y=pi*64-pi*36=Pi*28   fraction of Frame X's surface is not covered by a Frame Y= Pi*28/total area of the Frame X   =28/64=7/16   Answer is 7/16
<result>B</result>
Two circular frames are kept one above the other. Frame X has a diameter of 16 cm and Frame Y has a diameter of 12 cm. What fraction of the surface of Frame X is not covered by Frame Y?