A cube of 21cm length is cut into small cubes of side 7cm each. How much such small cubes can be obtained?

27

Volume of larger cube    = (21)³ cm³

Volume of smaller cube = (7)³ cm³

No. of such cubes          =  \(\frac{Volume\;of\;larger\;cube}{Volume\;of\;smaller\;cube}\)

                                     = (\(\frac{21}{7}\))³

                                     =  (3)³ = 27