Answer:
A. [tex] \frac{\sqrt 3}{3}[/tex]
Step-by-step explanation:
[tex]m\angle QSR = 180\degree - 150\degree \\ (Linear \: pair\: \angle s) \\ \\m\angle QSR = 30\degree \\ \\ \tan( \angle QSR) = \tan \: 30 \degree \\ \\ = \frac{1}{ \sqrt{3} } \\ \\ = \frac{ \sqrt{3} }{3} [/tex]
