Answer:
![F_1=366.67Hz](https://img.qammunity.org/2022/formulas/physics/high-school/ip51ogkhj1uih3gp8hp9o6t3w76x281k9b.png)
Step-by-step explanation:
From the question we are told that:
Frequency of 3rd harmonics
![F_3=1100](https://img.qammunity.org/2022/formulas/physics/high-school/bhj083lk27z4a4enyoaeva6mxex5sdem1k.png)
Frequency of 5th harmonics
![F_3=1833](https://img.qammunity.org/2022/formulas/physics/high-school/xqoriefsqp4k4z16wxscgj21l9f0n26512.png)
Generally the equation for Wavelength at 3rd Harmonics is mathematically given by
![\lambda_3=(4)/(3)l](https://img.qammunity.org/2022/formulas/physics/high-school/f1k9tnbwd1nk1breifk46meromhqd6lqf8.png)
Therefore
![F_3=(3v)/(4l)](https://img.qammunity.org/2022/formulas/physics/high-school/g6bqelppc6s2uxllpqauwvf5hmbs910mfg.png)
Generally the equation for Wavelength at 1st Harmonics is mathematically given by
![\lambda_1=(4)/(1)l](https://img.qammunity.org/2022/formulas/physics/high-school/cnwprbfb48s66sk6utvsmw4gab9i4d4qqn.png)
Therefore
![F_1=(v)/(4l)](https://img.qammunity.org/2022/formulas/physics/high-school/y0ax2ehyy0vw8ahc0qahpmj6hfojjukmw8.png)
Generally the equation for the frequency of the first harmonic is mathematically given by
![F_1=(F_3)/(3)](https://img.qammunity.org/2022/formulas/physics/high-school/2zei0ifw1n9e9xazjrpe4tpea2bu949lzc.png)
![F_1=(1100)/(3)](https://img.qammunity.org/2022/formulas/physics/high-school/jip0xbgnoyfmark1ftt20otpf7j9pe38k2.png)
![F_1=366.67Hz](https://img.qammunity.org/2022/formulas/physics/high-school/ip51ogkhj1uih3gp8hp9o6t3w76x281k9b.png)