Hi Aspirant!

As mentioned that length of minute hand is 10 cm, so average displacement will be 2*10=20 cm (from 6.00 AM to 6.30 AM as it moves, the starting point is 12 and ending point is 6). And the time taken is 30 minutes (given).

As we know, average velocity = average displacement/ time taken

therefore, average velocity = 20/30 = 2/3 cm/minute.

Hope it helps to clear your dilemma, thankyou!