Susan made a block with small cubes of 8 cubic cm volume to make a block ,3 small cubes long, 9
small cubes wide and 5 small cubes deep. She realizes that she has used more small cubes than she really
needed. She realized that she could have glued a fewer number of cubes together to lock like a block with
same dimensions, if it were made hollow. What is the minimum number of cubes that she needs to make the


block?
a) 114 b) 135c) 21 d) 71

• dimensions of small cube = 2*2*2
  
  Length of cube = 3 small cubes long = 6 cm
  Breadth = 9 small cubes wide = 18 cm
  Height = 5 small cubes deep = 10 cm
  
  Volume = 6*18*10 = 1080cm^3
  
  Volume of hollow cube = (6-4)(18-4)(10-4)
  = 168 cm^3
  
  total number of blocks needed = 1080-168 /8 = 912/8 = 114
  
• 12 years agoHelpfull: Yes(41) No(4)
• Ans = (3*9*5)-((3-2)*(5-2)*(9-2))=135-21=114
• 12 years agoHelpfull: Yes(22) No(4)
• volume of small cube =8*8*8 =512cm^3
  now required block of 3 small cubes long,9 small cubes wide and 5 small cube deep..
  so volume of block=(3*8)*(9*8)*(5*8)
  i.e. 512*(3*9*5)=512*(135)
  so min no of cubes required= 135
  thus ans is b)135
• 12 years agoHelpfull: Yes(4) No(17)
• 114 is the answerrrrrrrrrrrrrrr
• 12 years agoHelpfull: Yes(4) No(3)