A solid cube of volume 13824 cm3 is cut into 8 cubes of equal volumes. The ratio of the surface area of the original cube to the sum of the surface areas of three of the smaller cubes is:
Show answer & explanation
Correct answer: C
Explanation
Correct answer is option 3 i.e. 4 : 3
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Concept |
Understanding |
Application |
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Volume of cube = side3 Surface area = 6 × side2 |
Volume of big cube = 13824 cm3 (This data is not required) Let the volume of the big cube is 8x3 So, Side of big cube = 2x
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Volume of each small cube = 1x3 Side of each small cube = 1x Surface area of big cube = 6 × 2x × 2x = 24x2 Surface area of each small cube = 6x2 Surface areas of three of the smaller cubes = 18x2 Required ratio = 24x2 : (3 × 6x2) = 4 : 3 |