If the tension is 300 n, what is the difference in the speed of a wave traveling from one wire to the other?

   v₁ / v₂ = √μ ₂/μ ₁

Explanation:

The speed of a traveling wave on a string is given by

         v = √ T /μ

Where v is the speed of the wave, T the tension and μ  is the linear density of the string

Let's apply this equation to our case

               v₁ = √ T / μ ₁

               v2 = √ T /μ ₂

If the voltage of the two systems is the same

              T = v₁² μ₁ = v₂² μ₂

We cleared

            v₁² / v₂² = μ₂ / μ₁

             v₁ / v₂ = √μ ₂/μ ₁

the answer is to check all of them! they all apply well at least i think so!