Edge of cube=12cm
Volume of cube=axaxa
=12X12X12
=1728cm cube
Then it is cut into 8 equal sides therefore smaller cube =1728/8
=216cm cube
volume of cube =axaxa
therefore,216=axaxa
a=216*cube root
= 6cm
surface area of smaller cube =6(a)sq
= 6X(6)sq
=6X36=216cm sq
surface area of bigger cube =6X(12)sq
6X144=864cm sq
Ratio b/w their surface areas=216:864
=216/864
=1/4
=1:4