Question 288049
<pre><font size = 4 color = "indigo"><b>
{{{drawing(400,400,-2.5,2.5,-2.5,2.5, circle(0,0,2),circle(-1,0,1),
green(line(-2,0,0,0))

 )}}}

The green line is the small circle's diameter and also the 
large circle's radius.  Suppose the green line is 2 inches long.
Then the small circle's radius is 1, the red line:

{{{drawing(400,400,-2.5,2.5,-2.5,2.5, circle(0,0,2),circle(-1,0,1),
green(line(-2,0,0,0)), red(line(-1,0,-1-1cos(20*pi/180),-sin(20*pi/180)))

 )}}}

Area of small circle = {{{pi*radius^2=pi*1^2=pi*1=pi}}}

Area of large circle = {{{pi*radius^2=pi*2^2=pi*4=4pi}}}

Since the big circle's area is 4 times the small circle's area,
the small circle's area is {{{1/4}}} of the big circle's area
and {{{1/4}}} is the same as 25%. So the correct choice is b)

Edwin</pre>