A solid metal cuboid of 343 cm × 49 cm × 7 cm is melted and cubes of edge 7 cm are formed. The sum of surface area (in cm ) of total number of cubes formed is:
Answer & explanation
Correct answer: option 4
We know that,
Volume of cuboid = lbh
Volume of cube = side 3
Total surface area of cube = 6(side)2
We have,
Dimensions of cuboid = 343 cm × 49 cm × 7 cm
Edge of cube = 7 cm
Let the number of cubes = x
x × 73 = 343 × 49 × 7
x = (343 × 343) × \(\frac{1}{343 }\)
x = 343
Total surface area of 343 cubes = 343 × 6 × 7 × 7 = 100842 cm2