A boy want to make a cuboid of dimension 5m, 6m, 7m. from small cubes of .03 m3. later he realized he can make same cuboid by making it hollow. Then it take some cubes less. What is the no. of these cube.

• Total number of cubes=(5*6*7)/0.03=5000
  Hallow cube=total-inside
  Hallow cube=[(5*6*7)/0.03]-[((5-2)*(6-2)*(7-2))/0.03]=5000-2000=3000
  Hallow cube=3000
  Remove cubes=2000
  
• 13 years agoHelpfull: Yes(3) No(5)
• Total volume of cube = 5 * 6 * 7 = 210 m cube
  volume of smaller cube 0.03
  Total cubes reqd = 7000
  for hollow cube no. of small cubes reqd = 5/0.03 *4 + 6/.03 * 4 + 7/0.03 *4
  4 sides of 5,6 and 7 in the cube...so multiplied by 4
  which is approx 2000 so 5000 cubes have to be removed
  So the no. reqd is 5000
  
  
  
• 13 years agoHelpfull: Yes(2) No(1)