A hallow cube of 5cm is taken, with thickness of 1 cm.It is made of smaller cudes of 1 cm.If 5 faces of outer cude are painted,then totally how many smaller cubes surfaces reamin unpainted?
a)475 b)900 c)775 d)463

• TOTAL NO OF SMALLER CUBES=5*5*5-3*3*3=98 cubes
  so total faces = 98*6=588
  total no of painted cubes=5*25=125
  so unpainted cubes=588-125=463
• 14 years agoHelpfull: Yes(13) No(1)
• 463
• 14 years agoHelpfull: Yes(1) No(1)
• 463
• 14 years agoHelpfull: Yes(1) No(1)
• 588-25(no of unpainted surfaces)=588-25*5=588-125=463
  
  Ans d
• 14 years agoHelpfull: Yes(1) No(1)
• outer cube has 6 faces.
  each face has 25 small cubes bcoz each small cube is of 1 cm.
  5 faces of outer cube is painted and one is not so 6th face has 25 smaall cube with 6 faces of each so there are 25*6=150 faces unpainted.
  and remaining 5 faces of outer cube has total 125 small cubes(as one face has 25 smaal small cube so,25*5=125),here only outer face of the each of 125 cubes is painted so remaining 5 faces of each 125 smaal cube is not painted so there are 125*5=625 faces are unpainted.
  finally,150+625=775 faces of smaaler cubes remain unpainted.
  ans-c)775
• 14 years agoHelpfull: Yes(1) No(9)
• ans is 475
• 11 years agoHelpfull: Yes(1) No(0)
• ans d) 463
• 14 years agoHelpfull: Yes(0) No(2)
• d)463
• 14 years agoHelpfull: Yes(0) No(1)
• 5^3-3^3=98
  total face= 98*6=588
  5 faces of large are painted means 25*5=125
  then unpainted face is 588-125=463
• 14 years agoHelpfull: Yes(0) No(1)
• total no. of faces painted=5*(5*5)=125
  no. of cubes required to make the hollow cube= 25+25+18+15+15=98
  total no. of faces= 98*6=588
  so no. of unpainted faces(surfaces)=588-125=463
  
  ans (d) 463
• 14 years agoHelpfull: Yes(0) No(1)
• 463
• 14 years agoHelpfull: Yes(0) No(1)
• (5*5*5)-(3*3*3)=98
  98*6=588;
  588-(5*25)=463
  
• 14 years agoHelpfull: Yes(0) No(1)
• 588-25*n
  where n is the no of unpainted cube sides
  588-25(no of unpainted surfaces
  588-25*5
  588-125
  =463
  
  Ans d
• 13 years agoHelpfull: Yes(0) No(1)