A boy want to make a cuboid of dimension 5m, 6m, 7m from small cubes of .04 m3. Later he realized he can make same cuboid by making it hollow. Then it takes some cubes less. What is the no. of these cubes?

• volume of cuboid=5*6*7=210m3
  volume of inner cuboid=(5-1)*(6-1)*(7-1)=120m3
  therefore,volume of hollow cuboid=210-120=90 m3
  no of cubes required=90/.04=2250 cubes
• 10 years agoHelpfull: Yes(30) No(11)
• volume of cuboid=5*6*7=210m3
  no of cubes required = 210/0.04 = 5250
  volume of cube=0.04m3
  dimension of cube = 0.34m
  volume of inner cuboid = volume of hollow cuboid = [5-(0.34*2)]*[6-(0.34*2)]*[7-(0.34*2)] = 145.24m3
  no of cubes required for hollow cuboid = 145.24/0.04 = 3631
  no of cubes required = 5250-3631 = 1619 cubes
• 9 years agoHelpfull: Yes(6) No(3)
• (5*6*7)/0.04=6250
• 10 years agoHelpfull: Yes(0) No(17)
• volum of cuboid= 5*6*7=210
  volume of cube=.04
  total number of small cubes needed is = 210/.04=5250
  volum of inner cuboid=volume of hallow cuboid=(5-1)*(6-1)*(7-1) =120
  number of small cubes in inner cuboid(removed part or cubes in hallow) are=120/.04=3000
• 9 years agoHelpfull: Yes(0) No(4)
• Volume of solid cuboid= 5*6*7=210 m3.Length of each side of the small cube is 0.2 m. To make length 5m we have to arrange 25 small cuboids length wise. Similarly width wise 30 and height wise 35 cuboids. Now we are going to find volume of the hollow space .Total number of cubes we have to remove to make it hollow is (25-2)*(30-2)*(35-2).
• 9 years agoHelpfull: Yes(0) No(2)