At what level are you studying the subject?
There are two approaches possible here.
If you've only just started studying physics, then this is most likely a problem in dimensional analysis.
Assume that the frequency is a function of the mass per unit length, [tex]\mu[/tex], the total length of the wire, [tex]\ell[/tex] and the tension in the wire, [tex]T[/tex]
[tex]f=\mu ^\alpha \cdot \ell ^ \beta \cdot T^ \gamma[/tex]
Remember that the dimensions of the RHS must be exactly the same as those of the LHS.
I'll give you a lead, and say that the dimensions of frequency are: [tex][f]=[T]^{-1}[/tex]
If, however, you are studying this in a wave context, review your book and look at the section on waves in wires and look at the original question, since what you've posted can be interpreted as a multitude of things.