Answer:
The fundamental frequency is 159 Hz.
Step-by-step explanation:
Given that,
First frequency = 1113 Hz
Second frequency = 1431 Hz
Third frequency = 1590 Hz
Here, three frequencies are separated from each other by the multiple of 159
We need to calculate the fundamental frequency
As,
1113 Hz is the seventh harmonic of 159.
Hence, The fundamental frequency is 159 Hz.