A rotating disc of 1 m diameter has two eccentric masses of 0.5 kg each at radii of 50 mm and 60 mm at angular position of 00 and 1500, respectively. A balancing mass of 0.1 kg to be used to balance the rotor. What is the radial position of the balancing mass?
a) 50 mm b) 120mm c) 150mm d) 280mm