Answer
The required fractional increase in the tension of one wire is $~~0.020$
Work Step by Step
The string with a higher tension must produce a frequency of $606~Hz$, an increase of $1~\%$
Then the wave speed must have increased by $1~\%$
We can find the required increase in tension:
$1.01~v = \sqrt{\frac{(1+x)T}{\mu}}$
$(1.01~v)^2 = \frac{(1+x)T}{\mu}$
$1.020~v^2 = \frac{(1+x)T}{\mu}$
$1.020 = 1+x$
$x = 0.020$
The required fractional increase in the tension of one wire is $~~0.020$
