A man standing in front of a wall produces a sound and hears an echo after 3 s. He walks .X. m away from the wall and produces the same sound. Now he hears an echo after 5.25 s. Calculate distance he walked away from the wall. (Speed of sound in air is 340 m/s)

Explanation

To solve the problem step by step, we need to break it down into two parts based on the information provided.

### Step 1: Calculate the initial distance from the man to the wall
1. **Given**: The time taken to hear the echo is 3 seconds.
2. **Speed of sound in air (V)**: 340 m/s.
3. **Distance traveled by sound**: When the man produces a sound, it travels to the wall and back, which means the total distance is \(2d\) (where \(d\) is the distance from the man to the wall).
4. **Using the formula**:
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