test series closed

Question

#DS
suppose you have an array of 128 elements.which number is closest to the minimum number of binary element comparisons that would be necessary to sort the elements is?
I am getting 896,
as we have 128 elements for each element we take logn comparison because it is unsorted,
but the answer is given 891,
please guide?

Comments

What is binary element comparison .I think there is no such technical term.

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Sir,I only have this question,I am trying but unable to get it