A hollow cube of size 5cm is taken having thickness of 1 cm. It is made up of small cubes of size 1 cm . if 1 face of outer surface of cube are painted then find total how many faces of cube remain unpainted.

• 563
  its hollow cube therefore total cubes= 5^3-3^3=98
  total faces of 98 cubes=98*6=588
  one face of big cube is painted and cubes on one side is 25 and their one face is painted means 25 faces are painted
  so ans 588-25=563
  
  
• 9 years agoHelpfull: Yes(18) No(7)
• 6(5*5*5-3*3*3)=6(125-27)
  =6(98)
  =588
  outer surface 1 face contain 25 smaller face
  Unpainted face is=588-25=563
  Ans:563
• 9 years agoHelpfull: Yes(10) No(0)
• jasmine bhatia did it quite well n i think nothing can be better than that, but lets try to be even more clearer :D
  volume of 5cm cube=5^3
  volume of 3cm cube=3^3
  now try to imagine a cube of side 3cm made of air (just imagine).and we r pasting actual solid cubes of side 1cm over the faces,edges and corners of this imaginery cube. any guess what this will lead to
  ya exactly a CUBE OF SIDE 5cm :D
  so,volume of this hollow cube=5^3-3^3=98cm^3
  volume of cube of side 1cm=1cm^3
  total no of cubes = volume of hollow cube of side 5cm/volume of cube of side 1cm
  i.e....... =98cm^3/1cm^3=98
  total faces of 98 cubes=98*6=588
  one face of 5cm cube is painted and cubes on one side is 25 and their one face is painted means 25 faces are painted.
  so we need to deduct these 25 faces from total 588 faces to find the unpainted ones, so ans 588-25=563
  so ans 588-25=563
  
• 9 years agoHelpfull: Yes(5) No(0)
• 15 surface
• 9 years agoHelpfull: Yes(0) No(10)
• 579
  
  5^3-3^3=98 cubes
  number of faces 98*6=588
  no of faces in 1 side=9(becoz of thickness of 1cm)
  so unpainted faces=588-9 ie 579
• 9 years agoHelpfull: Yes(0) No(3)
• 11 will be the answer. scince the hollow cube has 6*2=12 surfaces. 1 of which is painted
  so 12-1=11
• 9 years agoHelpfull: Yes(0) No(1)
• 5^3-3^3=98
  
  one side means 25 cubes are painted
  
  so leaving 98-25=73....
• 9 years agoHelpfull: Yes(0) No(3)
• due to its hollow cube..for inner surface =6 faces are un painted
  for outer surface=5 faces are remaining so,total 11 faces are unpainted
• 9 years agoHelpfull: Yes(0) No(0)
• volume=(5^3-3^3)=98
  total faces=98*6=588
  588-100=488
• 9 years agoHelpfull: Yes(0) No(0)
• how can you find the value 3 in this solution.. please reply fast !!!!!!!!
• 9 years agoHelpfull: Yes(0) No(0)
• ans is 488
  its 588 - 25 * 4 = 488
  
• 9 years agoHelpfull: Yes(0) No(0)
• 488 is answer
• 8 years agoHelpfull: Yes(0) No(0)