A boy wants to make cuboids of dimension 5m, 6m and 7m from small cubes of .03 m3. Later he realized he can make same cuboids by making it hollow. Then it takes some cubes less. What is the number of the cubes to be removed?
a) 2000 b) 5000 c) 3000 d) 7000

please explain

• Volume=5*6*7=210m3
  Small cube vol=0.03m3
  no. of cube=210/0.03=7000
  
  So for making it hollow we have to leave 1m from each side.
  So
  Length=3m,Breadth=4m,height=5m
  So volume of hollow part=3*4*5=60m3
  no.of small cube=60/0.03=2000
  So we have 2 remove 2000 cube to make it hollow.
• 13 years agoHelpfull: Yes(25) No(4)
• volume of the cuboid = 5m * 6 m * 7m = 210 m3
  small cube volume = 0.03 m3
  no. of cubes = 210/.03 = 7000
  and to make hollow we have to remove 3m*4m*5m=60m3 volume
  then no. of cube= (60/.03)=2000
• 13 years agoHelpfull: Yes(17) No(5)
• why we'll subtract 1m 4m each side when the small cube doesnt hv 1m side its side s cube root of .03. please sm1 explain it asap
• 13 years agoHelpfull: Yes(10) No(2)
• at 1st 5*6*7/.03=7000
  to make the cube hollow
  ((5-2)*(6-2)*(7-2))/.03=2000
• 13 years agoHelpfull: Yes(6) No(3)
• volume of the cuboid = 5m * 6 m * 7m = 210 m3
  small cube volume = 0.03 m3
  no. of cubes = 210/.03 = 7000
  hence answer is d) 7000
• 13 years agoHelpfull: Yes(1) No(26)