In the figure, lines \(AB\) and \(CD\) are parallel. Two transversal \(PT\) and \(QS\) intersects at \(R\). If \(\angle QPR = 68^{\circ}\) and \(\angle RST = 42^{\circ}\), find \(\angle PQR\), \(\angle PTS\) and \(\angle PRQ\).
Answer:
1. \(\angle PQR\) \(=\) \(^{\circ}\)
2. \(\angle PTS\) \(=\) \(^{\circ}\)
3. \(\angle PRQ\) \(=\) \(^{\circ}\)