We know that segment RS is a diameter of the circle, this means that arcs RS an RST measure 180°. Now that we know that an using the ratio for arcs RT and TS given we have:
![\begin{gathered} RT+5RT=180 \\ 6RT=180 \\ RT=(180)/(6) \\ RT=30 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/hpcve7n46nzpybyx8qll5mu8mwqt837ryv.png)
Now, we know that an angle inscribed in a circle is half its intercepted arc, then we have:
![m\angle RST=(30)/(5)=15](https://img.qammunity.org/2023/formulas/mathematics/college/64badmhcckkq4opr1m53i5iwkjayasp91x.png)
Therefore, we have that arc RT is 30° and angle RST is 15°