Answer:
Option ( 1 )
Explanation:
This atom has a cub close pack structure, and therefore - the number of edge center present in X atoms = 4,
Number of unit cells present in X atoms = 6
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Now the 6th coordination number of X atom = 6 * 4 = 24,
So respectively, the 3rd coordination number of X = 8 -
And thus the ratio between the 6th coordination number and the 3rd coordination number = 24 / 8 = 3,
Option ( 1 )
Hope that helps!