A shaving mirror is used to see the enlarged view of the face while shaving. It is a concave spherical mirror. How far the shaving mirror should be placed to see the face magnified to thrice ? The focal length of the mirror is 10 cm.

Explanation

To solve the problem of how far the shaving mirror should be placed to see the face magnified to thrice, we will follow these steps:

### Step 1: Understand the given information
- The focal length (f) of the concave mirror is given as 10 cm. Since it is a concave mirror, we will consider the focal length as negative:
\[ f = -10 \, \text{cm} \]
- The magnification (m) required is 3 times:
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