A cuboid of sides 9 cm, 7 cm and 24 cm is melted to form a cube. What is the ratio of the total surface area of the cuboid to that of the cube? |
18 : 17 17 : 19 19 : 18 17 : 23 |
19 : 18 |
Sides of a cuboid = 9 cm, 27 cm and 24 cm Total surface area of cuboid, = 2(9 × 27 + 27 × 24 + 24 × 9) = 2(243 + 648 + 216) = 2214cm2 Volume of cuboid, = 9 × 27 × 24 = 5832 cm3. Let, side of cube = s cm According to problem, = s3 = 5832 = s = 18 Side of cube = 18 cm Total surface area of cube, = 6 × 182 = 1944 Required ratio, = 2214 ∶ 1944 = 41 ∶ 36 |