Multiple choice

A cube of edge 16 m is melted and recast into identical cubes, each of edge 4 m. What is the percentage increase in the surface area?

  1. 6400%

  2. 75%

  3. 300%

  4. 400%

  5. No change
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Surface area of old cube = 6A2                                          = 6 x 16 m x 16 m  
Surface area of 64 cubes, each of edge 4 m = 64 x 6a2                                                       = 64 x 6 X 4 m x 4 m Percentage increase = ((64 x 6a2 - 6A2)/6A2) x 100 = 300%

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