PA ∶ PB = 3 ∶ 2 and AB is diameter which is equal to 10 cm,⇒ PA = 3/5 × 10 = 6 cm and PB = 10 - 6 = 4 cmSince AO is the radius of the circle,∴ OP = 6 - 5 = 1 cmIn the same way,ND = 6 cm and NC = 4 cm∴ NO = 6 - 5 = 1 cmNow applying Pythagoras THEOREM in ΔOSN,⇒ OS2 = NS2 + NO2Since OS is the radius of the circle, OS = 5 cm⇒ 25 = NS2 + 1⇒ NS = 2√6∴ SM = (2√6 - 1) cm