Another quick physics problems (wave motion)

[djlightsout06]

A 30.0 m steel wire and a 20.0 m copper wire, both with 1.00-mm diameters are connected end to end and stretched to a tension of 150 N. How long does it take a transverse wave to travel the entire length of the two wires?
I really dont need an answer but rather something to get me going.

[Doc Al]

The speed of the wave depends on the tension and the mass per length:
v = \sqrt{\frac{T}{(M/L)}}
Where T = tension, M/L = mass per unit length of the wire.