Since the sum of the angles in a triangle is 180 degrees, we can use this information to find the missing angle.
Angle RPS = 180 - (Angle PRQ + Angle PST)
Angle RPS = 180 - (120 + 110)
Angle RPS = 180 - 230
Angle RPS = 50 degrees
So, the degree measurement of angle RPS is 50 degrees.