An object is held at 30 cm in front of a convex mirror of focal length 15 cm. At what distance from the convex mirror should a plane mirror be held so that images in the two mirrors coincide with each other?

Explanation

To solve the problem step by step, we will use the mirror formula and the properties of convex mirrors and plane mirrors.

### Step 1: Identify the given values
- Object distance (U) = -30 cm (negative because it is in front of the mirror)
- Focal length (F) = +15 cm (positive for a convex mirror)

### Step 2: Use the mirror formula
The mirror formula is given by:
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