A long sightedperson has least distance of distinct vision of 75 cm. What should be the focal length of the lens that is required for him to read a news paper at a distance of 25 cm?

Explanation

To solve the problem of determining the focal length of the lens required for a long-sighted person to read a newspaper at a distance of 25 cm, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Problem**:
- The person has a least distance of distinct vision of 75 cm, which means he can see objects clearly only when they are at least 75 cm away.
- He wants to read a newspaper at a distance of 25 cm, which is closer than his least distance of distinct vision.

...