Question 1098009
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<pre>
Step 1:  The area of each face of the smaller cube is  {{{864/6}}} = 144  square inches.


Step 2:  The edge length of the smaller cube is {{{sqrt(144)}}} = 12 inches. 


Step 3.  The edge length of the original cube is 12+4 = 16 inches.
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<U>Answer</U>.  The edge length of the original cube is 16 inches.



Solved.