The curved surface area of one cone is twice that of the other while the slant height of the latter is twice that of the former. The ratio of their radii is (a)   2:1        (b)  4:1       (c)  8:1        (d)  1:1

Explanation

To solve the problem, we need to find the ratio of the radii of two cones given certain conditions about their curved surface areas and slant heights. Let's break it down step by step.

### Step 1: Understand the given information
We have two cones, C1 and C2. The curved surface area of cone C1 is denoted as A1 and that of cone C2 as A2. The problem states:
- A1 = 2 * A2 (the curved surface area of one cone is twice that of the other)
- The slant height of cone C2 (L2) is twice that of cone C1 (L1), so L2 = 2 * L1.

### Step 2: Write the formula for the curved surface area of a cone
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