A cube of sides 9 is first painted red and then cut into smaller cubes of side 3. How many of the smaller cube have painted on exactly 2 sides? Pick:
A) 30
B) 24
C) 12
D) 8
E) 9

Rationale: n = side of big cube / side of small cube and no . of smaller cubes with two surfaces painted is ( n - 2 ) * 12 ( 3 - 2 ) * 12 = 12 ans answer : c
Answer: C