Answer:
F=84.0 Hz
Step-by-step explanation:
Using the equation f= n (v/2L), frequency equals number of loops times velocity over 2 times the length, in order to get 60.0 Hz of frequency from 5 loops, v/2L would have to equal 12. (12*5=60) v/2L is constant, so to find the frequency of 7 loops you would times 7 by 12 to get 84.0.
Hope this helped! :)