An object is kept in front of a concave mirror of focal length 15 cm. The image formed is three times the size of the object. Calculate the two possible distances of the object from the mirror.

Explanation

To solve the problem, we will use the mirror formula and the magnification formula for a concave mirror.

### Given:
- Focal length (f) = -15 cm (negative for concave mirror)
- Magnification (m) = ±3 (since the image can be real or virtual)

### Step 1: Use the magnification formula
The magnification (m) is given by the formula:
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