To solve the problem it is necessary to take into account the concepts related to beat frequency, i.e., The number of those wobbles per second.
The equation that describes the beat frequency is
For our given case we have that the frequency of the instrument is 440Hz and the Beat frequency is 5Hz therefore,
A) The frequency of the violin would be given by
B) <em>The violinist must loosen the string.</em> As the tightening increases the frequency, thereby increasing the number of beats from 5 to 6, i. e, on thightening the string, the frequency further increases as high frequency will be produced by short trings.