A tuning fork having n = 158 Hz, produce 3 beats/s with another. As we file the arm of unknown, beats become 7 then calculate the frequency of unknown.

Explanation

To solve the problem, we need to determine the frequency of the unknown tuning fork based on the information provided about the beats produced when it is played alongside a known tuning fork with a frequency of 158 Hz.

### Step-by-Step Solution:

1. **Understanding Beats**:
- The phenomenon of beats occurs when two sound waves of slightly different frequencies interfere with each other. The beat frequency is given by the absolute difference between the two frequencies.
- Mathematically, this is expressed as:
\[
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