For this case we have that if "y" varies directly with "x", we can propose:
[tex]y = kx[/tex]
Where "k" represents the constant of proportionality.
According to the data:
[tex]180 = kn\\n = k5[/tex]
We substitute the second equation in the first:
[tex]180 = k * k5\\180 = 5k ^ 2\\k ^ 2 = \frac {180} {5}\\k ^ 2 = 36[/tex]
We apply root:
[tex]k = \pm \sqrt {36}\\k = \pm6[/tex]
If k = 6, then[tex]n = 6 * 5 = 30[/tex]
Answer:
[tex]n = 30[/tex]
