Complete Question
The complete question is shown on the first uploaded image
Answer:
The answer is
% higher than

% lower than
Step-by-step explanation:
From the question we are told that
The first string has a frequency of

The period of the beat is

Generally the frequency of the beat is

Substituting values

From the question
for
having a higher tension
So


From the question


Substituting values

% higher than

For
having a lower tension

So



From the question


Substituting values

% lower than