Q:- A boy wants to make cuboids of dimension 5m,6m & 7m from small cubes of .03m^3.Later he realized that he can make some cuboids by making it hollow.Then it takes some cubes less.What is the number of cubes to be removed
a)2000 b)5000 c)3000 d)7000

• total no. of cubes needed to make cuboid from .03 cubes are (5*6*7)/.03=7000
  and no. of cubes needed to make it hollow is 5*6*7-(5-2)*(6-2)*(7-2)=150
  and total no. of cubes of .03 needed to make it hollow are 150/.03=5000
  so total no. of cubes to be removed are 7000-5000=2000
  so 2000 is the right ans.
• 12 years agoHelpfull: Yes(9) No(2)
• total no of cubes=5*6*7/0.03=7000
  for making it hollow we hav to remove(5-2)*(6-2)*(7-2)/0.03=2000 ans
  
• 12 years agoHelpfull: Yes(7) No(4)
• solved bu admin......same question answer i am just doing cntr+v here
  give comments about this guys......
  volume of the small cube = 0.03 m^3
  so side of this cube = cubic root of 0.03 m^3 = .312 m
  so after removing the outermost layer the dimensions for the inner cuboid will be (5-2*0.312), (6-2*0.312), (7-2*0.312)
  so total volume will be (4.376)*(5.376)*(6.376) = 150 m^3
  so no of cubes will be 150/0.03 = 5000
  so we can remove 5000 inner cubes
  
• 12 years agoHelpfull: Yes(7) No(4)
• VIKAS WHY U SUBTRACT 2 FROM EACH?
• 12 years agoHelpfull: Yes(6) No(0)
• beause we want hollow cude which is all the inner cubes - outermost cube
  ie (5*6*7)/.03 - (5-2)*(6-2)*(7-2)/.03 = 2000
• 10 years agoHelpfull: Yes(2) No(0)
• nikhilmestri@gmail.com
• 12 years agoHelpfull: Yes(0) No(0)