A metal sheet 27 cm long 8cm broad and 1 cm thick is melted into a cube. The difference between the surface areas of two solids is__________?

A. 284 cm²
B. 286 cm²
C. 296 cm²
D. 300 cm²

Explanation:

Volume of sheet = (27 × 8 × 1)cm³ = 216 cm³

Volume of cube formed = 216 cm³

Therefore, Edge of the cube = (6 × 6 × 6)^1/3 = 6 cm

Surface area of original cuboid = 2 (27 × 8 + 8 × 1 + 27 × 1) cm² = 502 cm²

Surface area of the cube formed = [6 × (6) ²] cm² = 216 cm²

Therefore, Difference in areas = (502 – 216)cm²= 286 cm²

Related Mcqs:

The edge of three cubes of metal is 3 dm, 4 dm and 5 dm. They are melted and formed into a single cube. Find the edge of the new cube?
A. 3 dm
B. 4 dm
C. 5 dm
D. 6 dm
Three cubes of metal whose edges are 9, 12 and 15 cm respectively, are melted and one new cube is made. Find the edge of the new cube?
A. 21 cm
B. 19 cm
C. 32 cm
D. 18 cm
The edges of three iron cubes are 6cm; 8cm; 10cm respectively. A new cube was made by melting them. Find the edge of the new cube?
A. 8 cm
B. 12 cm
C. 14 cm
D. 10 cm
A large cube is formed from the material obtained by melting three smaller cubes of 3, 4 and 5 cm side. What is the ratio of the total surface areas of the smaller cubes and the large cube?
A. 2 : 1
B. 3 : 2
C. 25 : 18
D. 27 : 20
The ratio of the volumes of a cube to that of the sphere which will fit inside the cube is________?
A. 4:3
B. 4:2
C. 4:4
D. 6: π
A rectangular field 30 m long and 20 m broad. How much deep it should be dug so that from the earth taken out, a platform can be formed which is 8 m long, 5.5 m broad and 1.5 m high where as the earth taken out is increase by 10/5?
A. 12 cm
B. 10 cm
C. 18 cm
D. 24 cm
A wooden box of dimensions 8m x 7m x 6m is to carry rectangular boxes of dimensions 8cm x 7cm x 6cm. The maximum number of boxes that can be carried in 1 wooden box is?
A. 1200000
B. 1000000
C. 9800000
D. 7500000
The sides of a cube are in the ratio 1:2 the ratio of their volume is__________?
A. 1:2
B. 1:4
C. 1:8
D. 2:1
The spherical ball of lead 3 cm in diameter is melted and recast into 3 spherical balls. The diameters of two of these are 1 ½ cm and 2 cm respectively. The diameter of third ball is?
A. 2.66 cm
B. 2.5 cm
C. 3 cm
D. 3.5 cm
A cistern of capacity 8000 litres measures externally 3.3 m by 2.6 m by 1.1 m and its walls are 5 cm thick. The thickness of the bottom is__________?
A. 90 cm
B. 1 dm
C. 1 m
D. 1.1 cm