Circles I and II have radii 8 and 4 respectively. A sector of A degrees is shaded in circle I and a sector of B degrees is shaded in circle II (see the figure below). If the shaded area in circle I = 1/4th of the shaded area in circle II, what is A:B ?
Note: If you carefully read the question and think, you can solve it in 15-20- seconds after reading it.