A man with normal near point (25 cm) reads a book with small print using a magnifying glass : a thin convex lens of focal length `5 cm`.
What are the closest and the farthest distances at which he can read the book when viewing through the magnifying glass ?

Explanation

To solve the problem step by step, we will calculate the closest and farthest distances at which a man can read a book using a magnifying glass (a thin convex lens) with a focal length of 5 cm.

### Step 1: Understand the Given Information
- **Normal near point (D)**: 25 cm (the closest distance at which the man can see clearly without any optical aid)
- **Focal length of the lens (f)**: 5 cm

### Step 2: Calculate the Closest Distance
To find the closest distance (u) at which the man can read the book through the magnifying glass, we will use the lens formula:
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