A circle is denoted by its centre. So point O is the centre of this circle.

I understand the denotation sir however no information has been given in the question as to where this center lies(O) or if any of the points mentioned in the question are part of this circle. The intersection of those two chords is denoted by X so i'm not sure where to even start in this problem. Is there a simple diagram which can demystify this confusion?

To find SX= (PX * QX)/XR= 5 * 3 /2 = 7.5
To find the midpoint of chord PQ and RS,we have
Midpoint of PQ(M)=5+3=8/2=4
Midpoint of RS(N)=7.5+2=9.5/2=4.75
Now we have PM=QM=4 and SN=RN=4.75

OM=NX=RN-RX=4.75 - 2 =2.75
To find the radius which is OP=OQ
We use Pythagoras theorem,
OP=square root ( sqr(PM) +Sqr(OM))
=square root (4×4 + 7.75x7.75)
=square root(16+7.56)
Radius =square root(23.56)