The arc length of SP and QR is 55° because of supplementary law. 180 - 125 = 55, if you can see how it can work
Now. arc QOS equals ROP, so it = 125°
To find PQR, you add 55 + 125 + 55, because you are passing 3 of those arcs while going to R in PQR, so the answer is:
235°
MADE A FATAL ERROR: the angle 50° is supposed to be 55°