After the surface area of a cube is painted the cube is cut into 64 smaller cubes of same dimensions. How many have no face painted? 1 face painted? 2 faces painted? 3 faces painted?
Note that lateral surface area of a cylinder is the circumference of base x height of cylinder. Can we write lateral surface area of a cuboid as perimeter of base x height of cuboid?
Total surface area of the cuboid (a) = 2[lb + bh + hl]
= 2 [(60 x 40) + (40 x 50) + (50 x 60)] cm2
= 2[2400 + 2000 + 3000] cm2
= 2[7400 cm2] = 14800 cm2
Total surface area of the cuboid (b) = 2[lb + hh + hl]
= 2[(50 x 50) + (50 x 50) + (50 x 50)]
= 2[2500 + 2500 + 2500] cm2
= 2 [ 7500 cm2] = 15000 cm2
Since the total surface area of the second (b) is true.
∴ Cuboid (a) will require lesser material.