The velocities of three particles of masses 10 kg, 20 kg and 30 kg are 10i, 10j and 10k m/s, respectively. What is the velocity of their centre of mass?

The velocities of three particles of masses 10 kg, 20 kg and 30 kg are 10i, 10j and 10k m/s, respectively. What is the velocity of their centre of mass?
 
(a) (i + 2j + 3k) m/s
 
(b) 10 (i + j + k) m/s
 
(c) (10i + 20j + 30k) m/s
 
(d) (3i + 2j + k) m/s
 
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This interesting question is from System of Particles topic in section System of Particles and Rotational Motion of Physics – Class 11
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