The near and far points of a person are at `40 cm` and `250cm` respectively. Find the power of the lens he/she should use while reading at `25cm`. With this lens on the eye, what maximum distance is clearly visible?

Explanation

To solve the problem step by step, we will follow these steps:

### Step 1: Understand the Problem
We need to find the power of a lens that allows a person to read at 25 cm, given that their near point is at 40 cm. We also need to determine the maximum distance that can be clearly seen with this lens.

### Step 2: Identify the Given Values
- Near point (N) = 40 cm
- Far point (F) = 250 cm
...