Ahollow cube of size 5 cm is taken with a thickness of 1 cm. it is made of smaller cubes of size 1 cm. if 3 faces of the outer surface of the cube are painted totally how many faces of the smaller cubes remain unpainted?
525
900
825
513

• totally 513 sides remain unpainted.
  there are totally 98 small cubes and therefore 588 sides and if 75 sides are painted there will be 513 sides remain unpainted
• 13 years agoHelpfull: Yes(15) No(0)
• No. of small cubes required to make the bigger cube= (5*5*5-(5-2)*(5-2)*(5-2))/1*1*1 = 98
  Small cubes surfaces on one side of bigger cube= 5*5= 25
  Total no of sides of small cubes= 98*6 = 588
  But 3 faces of the outer surface are painted i.e. 3*25= 75 surfaces of smaller cube are painted already
  So remaining surfaces to be painted are= 588-75=513
• 13 years agoHelpfull: Yes(7) No(0)