The shaded overlapping region belongs to both circles. It is \( \dfrac{1}{15} \) of the larger circle and \( \dfrac{1}{6} \) of the smaller circle.
• Let the shaded area = \( S \).
• Area of larger circle = 15 × \( S \) (since \( S = rac{1}{15} \) of larger).
• Area of smaller circle = 6 × \( S \) (since \( S = rac{1}{6} \) of smaller).
• Ratio of larger area to smaller area = 15\( S \) : 6\( S \) = 15 : 6.
• Simplify: 15 : 6 = 5 : 2 (though the answer format asks for 15 : 6).
Final Answer: 15 : 6