Determine Tension and Length of 50g Guitar String Oscillates at 1280Hz

[Ry122]

a third harmonic of a 50g guitar string oscillates at a frequency of 1280hz. the wavelength is 30cm
determine the tension in the string and the string length.

my attempt:
the 3rd harmonic of a guitar string is 3/2 times the wavelength so the length of the string is 45cm.
so mass per unit length is .05/.45=.111kg/m
v=f(lambda)
so v =384ms^1
V=sqrt(T/mu)
so 384=sqrt(T/.111)
T therefore is =16367.616N
isnt this value for tension too large to be correct?
where am i going wrong?

 

[davieddy]

I can't spot an error, the original question sounds plausible
and yet this tension is ridiculously high.
50g sounds a bit heavy, but even so...