Geometry

Question Analysis

The main focus is using the ratio of the radii of two concentric circles and the area of the ring between them to find the outer radius. We'll set up an equation based on the ring - area formula and the given ratio to solve for the unknown radius.

Key Concept Explanation

The area of a ring is calculated by the formula , where  is the outer radius and  is the inner radius. When the radii are in a ratio, we can represent them as multiples of a common variable to simplify the calculation process.

Step - by - Step Solution

1. Let the outer radius  and the inner radius  (x > 0).

2. Substitute into the ring - area formula: .

3. Since , set up the equation

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